ACIS and a vaccumm leak?

[Chris R]

So I definitely get that surge at 3500 to 3800 rpm. After some research, it seems my ACIS is screwed. I need to e-mail the owner, but I have a JDM transplant motor. Possibly an ex cresseda motor, but the throttle body was changed out. What's the best way to go about fixing the ACIS?

Any pics would be greatly appreciated, as I have no idea what I'm looking for here.

I read that it's best to clean the intake, and if I were, how would I go about doing that without damaging anything?

But my car also idles funny, it revs a couple hundred rpms, between 500 and 700, in a rhythmic fashion. It doesn't do this all the time.

I have to charge the fuel pump from an interior switch before I start the car. Not sure if that would have much do it with it once I got it started. It was put there by the previous owner, I've only had this car about a week.

I probably need to check for a leak or two hoses that got switched up. What's the best way to go about doing that?

I

[Chris R]

Alright, did some error checking.

I got codes 21 - Oxygen sensor

41 - Throttle Position Sensor

and 43 - Starter

Could the throttle position sensor be responsible for the rough idle?

[CRE]

A problem with the TPS can cause idle issues, but it's usually related to the IDL switch in the TPS (see code 51). Test the TPS and see if it's properly calibrated... if it is you may just want to replace it. It is a wear component after all.

[Chris R]

It's probably got some mileage on it, but I'm thinking of replacing it anyways.


Anyone got any info on ACIS? I posted over and Supraforums and no one said much there either. If there's a post on this that I'm missing, please link me to it, but I searched.

[AJ'S 88NA]

It's probably got some mileage on it, but I'm thinking of replacing it anyways.


Anyone got any info on ACIS? I posted over and Supraforums and no one said much there either. If there's a post on this that I'm missing, please link me to it, but I searched.
There's some info on it in the NA stickies.

[al.]

Anyone got any info on ACIS? I posted over and Supraforums and no one said much there either. If there's a post on this that I'm missing, please link me to it, but I searched.

not much practical info, but there's a wiki entry that briefly explains its function and actuation - ACIS (http://en.wikipedia.org/wiki/Acoustic_Control_Induction_System)

and hello, i'm new here :drink1:

[CRE]

Start by verifying that all of your vacuum lines are routed properly and that there are no leaking lines. Personally, I would just replace them all so i could be sure in the future that they're going to be in good shape. A vacuum leak can also cause the roaming idle, but I'd look at the TPS first.

Look at the following for routing information.
http://www.cygnusx1.net/Supra/Library/EPC/291410/catalog.aspx?F=1708&P=2


Fix the error codes too. I don't know if any of those will cause the ECU to not activate the ACIS VSV, but I promise they're not helping.

[Chris R]

I just wanted to give a quick update. I ordered a new TPS. On my first test drive, it ran like a bat out of hell. The torque in the low range was all there. Perfect.

And then I realized that somehow we forgot to plug it in.

So I plugged it in, and the idle was a bit rougher, and it seems like it does not want to rev above 2000 rpms.

I ordered mine from rockauto parts. It was for the 7mge FI (fuel injected?). The 7mge listed as MFI did not have a TPS.

I read that the 89+ were different from the pre 89's, and this one is about 90 degrees off. So I'm guessing that's part of the problem.

Aside from that, what is the throttle position sensor's job? There is a manual throttle cable, just like in my 5SFE Celica, so I'm just wondering if it affects the air/fuel ratio, or what. It seemed to run better without the TPS, but I'd rather not play around and harm the motor.

[HommerSimpson]

I just wanted to give a quick update. I ordered a new TPS. On my first test drive, it ran like a bat out of hell. The torque in the low range was all there. Perfect.

And then I realized that somehow we forgot to plug it in.

So I plugged it in, and the idle was a bit rougher, and it seems like it does not want to rev above 2000 rpms.

I ordered mine from rockauto parts. It was for the 7mge FI (fuel injected?). The 7mge listed as MFI did not have a TPS.

I read that the 89+ were different from the pre 89's, and this one is about 90 degrees off. So I'm guessing that's part of the problem.

Aside from that, what is the throttle position sensor's job? There is a manual throttle cable, just like in my 5SFE Celica, so I'm just wondering if it affects the air/fuel ratio, or what. It seemed to run better without the TPS, but I'd rather not play around and harm the motor.


Did you calibrate the new tps? And yes you need it.. it tells the ecu were the trottle is... everything works together telling the ecu what it needs to do... screw 1 thing up and you can wack the afr out and run lean and next thing you know you got holes in pistons....

[Kckazdude]

The TPS only differentiates between turbo and NA. There is no year break in them.
Be sure to install the TPS as outlined in the TPS.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=101

[Chris R]

Did you calibrate the new tps? And yes you need it.. it tells the ecu were the trottle is... everything works together telling the ecu what it needs to do... screw 1 thing up and you can wack the afr out and run lean and next thing you know you got holes in pistons....

I thought I had read that the TPS doesn't need calibration, it just needs to be installed. I'll search again.

The weird thing is that it ran great without the TPS plugged in. I dunno, but the old one is on there now just to keep it drivable.

Come to think of it, given how the old TPS caused me to loose some of that low end punch, what I'm guessing is that the old TPS is wrong. I looked at the newer TPS and compared it to one of the pictures in a thread around here, and the "tabs" set vertical, pointing to the screw holes. The old one is 90 degrees off, and the tabs set horizontal.

So the new one is probably the right part after all, it just may need calibration.



The TPS only differentiates between turbo and NA. There is no year break in them.
Be sure to install the TPS as outlined in the TPS.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=101

Sorry, I missed this post. It was in one of the threads I found in search, but it said that there was a difference in that the throttle position sensors were 90 degrees off from one another. And that describes exactly the difference I'm seeing in the two here in front of me.

I somehow did not connect the dots when I read about the thickness gauge between the throttle stop screw and the screw lever. I guess I'm not seeing if that is for calibrating, or just to check and make sure the throttle cable assembly is acting properly.

[jetjock]

1) The TPS needs to be calibrated to the TB.

2) Not weird at all the engine runs good with it unplugged. It's supposed to. However if you have the wrong one plugged in (or the right one but not adjusted) it'll be a different story.

[Chris R]

I still have no calibrated it, I'm planning on grabbing my dad's multi-meter tomorrow and doing it.

We had another throttle body that came with the car, and that seemed to work perfectly with the new TPS, so we swapped them out. The throttle bodies were the same size, and all the lines hooked up, it just seemed that the TPS was the only difference.

On the old throttle body, if I installed the new TPS by sliding it in with the wire connector facing up at a 90 degree angle, and then sliding it clockwise, the sensor would lock the throttle wire in such a way so that it would not move. We had to hold the throttle level at full throttle to install the sensor, and that did allow it to move.

When the new sensor was connected, the car would stop revving at about 1.8k rpms and it would just decel down to 1000.

Now, on the new throttle body, it acts just like it did before before I touched anything on the car at all. I tried adjusting it a bit by hand with the motor on, but never really got it to act right.

It still lacks a bit of low end, and on the highway in 5th I still get a delayed (two or three seconds) throttle response.

So I'm going to attempt to calibrate it tomorrow and see where that gets me.

Part of me wishes I would have just left the damn thing unplugged the first time I put the new TPS on the older throttle body. For some reason the car ran beautiful, and pulled great. And then I decided to plug it in and it all went to hell. :3d_frown:

Looking at the symptoms, I had attributed those to a bad TPS, along with that code 51 I was getting. If anyone has any other recommendations feel free to chime in.

[Chris R]

Another update.
We're trying to calibrate it now. Hooking an ohm meter up to it, I've been slowly moving it clockwise until it deflects, and then moving it ever so slightly counter clock wise until the meter goes back down to zero.

We don't have a feeler gauge, and that's a problem. But I figured by calibrating it I'd just try and get it as close as possible.

The issue, however, is that since adjusting it (my first time was pretty sloppy, not gonna lie) it has been misfiring. I kept the car running and the TPS plugged in and tried moving it throughout it's range, and it misfired the entire time.

Any ideas? I realize that I need a feeler gauge to do this right, but would that throw it off far enough to cause a misfire?

-edit- Pulled the plug closest to the radiator, there's oil in there. Meh. Guess that explains the lost oil. - removed oil, misfire went away, sort of. It'll idle great for a couple of seconds, at about 700 to 800. It'll slip down to 600 and idle rough, and it'll alternator a bit. Ont he highway now, it's kind of like it gurgles in certain RPM ranges. The delay in the throttle is still there.

So I think I'm dealing with a couple problems here, and not just the TPS. Timing may also be an issue, we have not checked that.

It'd be a good idea to change out the valve cover gasket since some of the screws were loser than what they should be, and there was oil in the spark plug closest to the front of the car. The plug furthest to the back did not have that much oil in it, nor the second one in line. We have not checked the ones underneath the throttle body yet.

For anyone reading this, hopefully I'm not confusing the hell out of you. I promise my thoughts are not as random as they appear on here. ;)

[Chris R]

I mentioned earlier that we switched out the throttle bodies. I think the newer throttle body that we switched in might be connected to the misfire problem.


-edit- Pulled the plug closest to the radiator, there's oil in there. Meh. Guess that explains the lost oil. - removed oil, misfire went away, sort of. It'll idle great for a couple of seconds, at about 700 to 800. It'll slip down to 600 and idle rough, and it'll alternate a bit. On the highwa it gurgles in certain RPM ranges. The delay in the throttle is still there.

I took my dad out with me on this second run, he said that gurgle I was describing is a pretty bad misfire.

Before the highway run with my dad, we cleared the ECU. It seems that whenever we clear the ECU, on the first time starting up it idles incredibly high, around 2500. On the highway it acts normal, no huge misfire issues are prevalent. When the car is shut down and started a second time, the misfire returns and the issues becomes worse when the car is being driven.

I'm wondering if this has anything to do with the MAF sensor, and if that is related to the throttle body. We hooked all the hoses up to the newer throttle body right, so I don't believe that is an issue.

As for the oil that was found in the spark plugs, I think that just compounded the problem of the misfire, it definitely was not the source. Car still seems to run rich too, the older throttle body was pretty dirty and black on the inside.

There could also be an ECU problem in there somewhere. The previous owner said that the guy who had the car before hand put, I quote, a "plug and play ecu" from Toyota in the car. Who knows. I think I need to replace that anyways, since I have no idea how that thing is tuned, if it's chipped, or whatever.

On top of all this, the TPS still hasn't been calibrated 100% correct. I plan on picking up some feeler gauges at an auto parts store tomorrow. We're gonna throw the older throttle body on, with the old TPS, calibrate it and see if that does anything whatsoever.

[AJ'S 88NA]

I mentioned earlier that we switched out the throttle bodies. I think the newer throttle body that we switched in might be connected to the misfire problem.



I took my dad out with me on this second run, he said that gurgle I was describing is a pretty bad misfire.

Before the highway run with my dad, we cleared the ECU. It seems that whenever we clear the ECU, on the first time starting up it idles incredibly high, around 2500. On the highway it acts normal, no huge misfire issues are prevalent. When the car is shut down and started a second time, the misfire returns and the issues becomes worse when the car is being driven.

I'm wondering if this has anything to do with the MAF sensor, and if that is related to the throttle body. We hooked all the hoses up to the newer throttle body right, so I don't believe that is an issue.

As for the oil that was found in the spark plugs, I think that just compounded the problem of the misfire, it definitely was not the source. Car still seems to run rich too, the older throttle body was pretty dirty and black on the inside.

There could also be an ECU problem in there somewhere. The previous owner said that the guy who had the car before hand put, I quote, a "plug and play ecu" from Toyota in the car. Who knows. I think I need to replace that anyways, since I have no idea how that thing is tuned, if it's chipped, or whatever.

On top of all this, the TPS still hasn't been calibrated 100% correct. I plan on picking up some feeler gauges at an auto parts store tomorrow. We're gonna throw the older throttle body on, with the old TPS, calibrate it and see if that does anything whatsoever.You have to take care of one thing at a time. Yes the oil in the plug wells will cause a miss fire. Hard to tell how old the plugs are I'd replace them while you're at it and check your wires.

And the TPS has to be calibrated right our you will get the high idle and other problems you mentioned. The TB will get dirty due to the PVC hoses and poor maintainance, I.E. air filter, long oil changes etc.

[Chris R]

You have to take care of one thing at a time. Yes the oil in the plug wells will cause a miss fire. Hard to tell how old the plugs are I'd replace them while you're at it and check your wires.


The plugs are pretty new, according to the previous owner. Same with the wires. It might be a good idea to change them. Before I do though, I want to try and get the TPS calibration out of the way so I don't spend a lot of money chasing ghosts. Will a TPS cause a miss, or can I just rule that out of the misfire problem?



And the TPS has to be calibrated right our you will get the high idle and other problems you mentioned. The TB will get dirty due to the PVC hoses and poor maintainance, I.E. air filter, long oil changes etc.


I think the previous owner did do a decent job of maintenance. The high idle only happens on the first start up after clearing the ECU. Aside from that, it may idle at 1000 at it's highest.

[AJ'S 88NA]

The miss is most likely from the oil in the plug wells. If it's a lot yu have to make sure you get the ends of the plug wires clean also.

[jetjock]

The TPS is not the cause of your misfire. Plus you're putting WAY too much focus on setting it. The feeler gauge thing is not critical and is mainly for emissions. Just set it using code 51 and as long as you don't end up with a 41 afterwards move on to what's really wrong with the engine...

[Chris R]

The miss is most likely from the oil in the plug wells. If it's a lot yu have to make sure you get the ends of the plug wires clean also.

We cleared most of the oil out of the plug wells. We'll go back and clear off the wires a bit more thoroughly. The plugs were almost completely underneath oil at first. But we cleared a good 90% of it out. It's no longer touching the plugs.



The TPS is not the cause of your misfire. Plus you're putting WAY too much focus on setting it. The feeler gauge thing is not critical and is mainly for emissions. Just set it using code 51 and as long as you don't end up with a 41 afterwards move on to what's really wrong with the engine...

Gotcha. I'll check for codes again. From reading the threads about adjusting the TPS, I got the impression that it had to be nearly perfect or the car's performance would suffer.

I've adjusted it to the best I can, so you're right, it's time to move on. If the TPS will not cause a misfire then we'll take a better look at the plugs when we switch throttle bodies back and see if we can move on from there.

[suprarx7nut]

Did you take any of the plugs out? If so, you probably dumped some oil into the cylinder and that would cause some smoking and a nasty misfire until the oil has burned off. That happened to me and I thought I messed something up by changing plugs, but it was just the oil. 20 mins of highway driving fixed it and I'm sure it shortened the life of the plugs.

[Chris R]

Did you take any of the plugs out? If so, you probably dumped some oil into the cylinder and that would cause some smoking and a nasty misfire until the oil has burned off. That happened to me and I thought I messed something up by changing plugs, but it was just the oil. 20 mins of highway driving fixed it and I'm sure it shortened the life of the plugs.

How nasty was the misfire?


We swapped throttle bodies, and checked the plugs today and cleaned the oil out.

On the first start up it idled pretty smooth, but on the highway it started sputtering, delayed reaction, and general lack of power. So the throttle body wasn't the issue at all in this case.

When working with it, we started it up and ran it numerous times. The idle seemed to get worse (we were going through checking sensors, engine codes, so on and so forth).

We cleared the ECU and it's only throwing a code 43 now.

On a side note, the previous owner did have a setup where I had to charge the fuel pump to get it started easily. That stopped working, so it's pretty hard to get it started right. I'm not sure how this occured. He had swapped out a gas tank to the "turbo" gas tank, which holds 16 gallons.

I should have mentioned that before, but I was so focused on the spark plugs and the TPS that it slipped my mind, my bad guys. If the fuel pump is indeed going bad, will that cause a rough idle, and the sputtering when revved? The sputtering has only occurred since we started messing with the TPS. Previously, it was pretty smooth under load except for a small misfire (which is what we've been trying to fix here.)

Lastly, I'm throwing in a used ECU. I have no idea what any of the previous owners did to it, and that could be a cause of the problem too. So it's better to just return to stock and see where that gets me.

[jetjock]

Well, you could always measure fuel pressure and see. Pump current would also be helpful.

There's absolutely no need to prime the fuel system so why he did that is beyond me. If he had a code 43 I could maybe see it but that's a dumb way around the problem. That said you can always prime it by jumping B+ and FP in the diag block.

[Chris R]

Well, you could always measure fuel pressure and see. Pump current would also be helpful.

I plan on it. It's possibly there could be a leak somewhere.




There's absolutely no need to prime the fuel system so why he did that is beyond me. If he had a code 43 I could maybe see it but that's a dumb way around the problem. That said you can always prime it by jumping B+ and FP in the diag block.

I figured that a fuel pump was either a "It works, or it doesn't" item, but I could be wrong on that.

I'm not sure what codes he had. I had a 41, 21, and 43. 41 and 21 have gone away, leaving me with 43.


I'm going to try and get in contact with him and see if he replaced the pump and filter when he replaced the tank.

[Chris R]

It's been awhile. Haven't had much of a chance to work on it this week.

I ordered quite a bit of gaskets, the valve cover, valve cover #3, small ones for the valve cover #3 bolts. I figure that we'll figure the oil leakage problem, and while we're tearing stuff down we'll take a good hard look at the spark plugs.

I have some questions for you guys, and some pictures to help out.

Starting off, started it today. It takes effort to start up. It'll just crank, and then die. If you play with the throttle and manage not the flood it, the car will start, and then idle high.

After my dad and I poked around the engine bay a bit, I took it out for a drive. For the first couple miles, it runs smoothly, but if you get into the throttle, the car hesitates and doesn't really respond.

After a couple of miles I turned around, and at this point if I get on the car, it misfires. The best way I can describe the sound coming from the exhaust is that it sounds like a motorcycle under acceleration. On idle, it just kind of hovers at 600-700, it idles rather roughly. The car only did the bluh- bluh-bluh thing on the second half of the drive, which was only about 4 to 5 miles.

I tested the fuel pump by jumping the connections that the TSRM lists. I can't remember the exact ones, FB and B+, I think, or something.

When I do, I get a buzzing sound from this area. I'm thinking it's that steel box, the fuel pump relay?
My dad touched the fuel rail when we did this. He could not feel any fuel going through and we couldn't hear anything either. But later on the car started and drove, so this problem seems intermittent.

http://i305.photobucket.com/albums/nn214/chrisrobinette/P7240008.jpg

This is the same place that emits the sound when the switch that the previous owner installed to prime the fuel pump. I can not get a hold of him to find out why.

Thinking that in some way this might be a pressure problem, we poked some more around the engine bay, and noticed that this line (#2 on the picture) was crimped. We're not sure if this was a fuel line is. We're thinking that if it's crimped, then that might be part of the problem.

http://i305.photobucket.com/albums/nn214/chrisrobinette/P7240005.jpg

The #1 circle in that picture is a loose connection we found, but we couldn't figure out what it goes to. It looks like one of the connectors for the injectors, but all those had plugs in them.

We plan to go to the local mechanic and see if he can help us test the fuel pressure. I've looked at the diagram for the tsrm, but I'm having trouble identifying the fuel line. I took a picture of the area. What line should I be looking at here?

http://i305.photobucket.com/albums/nn214/chrisrobinette/P7240006.jpg

I've seen the AFM listed as a cause for the car starting, and then dying. Again, the TSRM confused me because I couldn't actually locate it on the engine so I could test it with a multi-meter. I'm thinking that it's hanging off the black thing that is directly to the right of the power steeling reservoir, in the intake hose. But I'm not quite sure.

http://i305.photobucket.com/albums/nn214/chrisrobinette/P7240007.jpg

Lastly, this isn't really connected, but we found this in the main fuse box in the car.
http://i305.photobucket.com/albums/nn214/chrisrobinette/P7240004.jpg
That arched thing is pretty burnt. We aren't sure if that's just an odd fuse, or if the previously owned rigged it up. The fuse on top of the box has "ALT" in it. I can't remember the rest of the title, and I injured my leg last week, the car is long walk out the barn away, or else I'd go check it right now.

[CRE]

Okay, a crimped pipe is a bad thing... can't see what you're referring to in that picture, but if it's crushed it probably should be replaced.

The VAF (AFM) is the aluminum box that's bolted to the air filter housing. It's got the big black plastic "D" on the top, your pic shows it very well.

The burnt, arched thingy is a fusible link. If it's burnt and in poor shape replace it. You may replace it with a sealed unit instead of the stock fusible link wire if you wish. It is NOT just a regular piece of wire! If you replace it replace it with the proper part.

Buzzing from the fuel pump relay isn't the sign of a healthy relay... probably should look into that further and replace it if needed. This relay and the attached resistor pack are used to switch the fuel pump from low and high, a bad relay can cause sluggishness or even prevent the car from operating. You could try bypassing it *temporarily* to see if that's the source of your problems.

[Chris R]

Okay, a crimped pipe is a bad thing... can't see what you're referring to in that picture, but if it's crushed it probably should be replaced.

We're planning on doing that today.



The VAF (AFM) is the aluminum box that's bolted to the air filter housing. It's got the big black plastic "D" on the top, your pic shows it very well.

Gotcha, thanks.



The burnt, arched thingy is a fusible link. If it's burnt and in poor shape replace it. You may replace it with a sealed unit instead of the stock fusible link wire if you wish. It is NOT just a regular piece of wire! If you replace it replace it with the proper part.


Definitely, we're not planning on rigging anything on this car unless we have to. Bad, lazy fixes will just cause me more problems later on.

The previous owner had to replace to alternator, I had forgotten that, so it might explain why it's in poor shape.



Buzzing from the fuel pump relay isn't the sign of a healthy relay... probably should look into that further and replace it if needed. This relay and the attached resistor pack are used to switch the fuel pump from low and high, a bad relay can cause sluggishness or even prevent the car from operating. You could try bypassing it *temporarily* to see if that's the source of your problems.


Okay, that'll work. We'll bypass it today and see what that does with the car.

Would sluggishness in any way include that putter/misfire the car does under load? Or would the relay just cause the car to not really respond to the throttle?

[Chris R]

Noticed today that the sputter starts when the car just starts to warm up. We didn't notice this before, but now I'm starting to wonder if it's a sensor problem somewhere.

What can do to help describe these problems better? I'm trying the best that I can, but I'm not that knowledgeable with cars, and my dad has more experience with carburetor stuff than fuel injected, so we're kind of stumped here. It's hard to know what information you guys need when I'm not entirely sure what I'm looking for myself. So if I need to give more information, please let me know so I can help you guys to help me.

[Chris R]

Looking up the resistance specs on the AFM, I have a couple questions about the tests. If it meets the resistance specs, is that a sign that its working? I've heard the TPS can still meet spec and not work, so I'm wondering if the same thing applies to the AFM.

CRE, in another thread you mentioned using a hair dryer to heat up the AFM to test it. Which part do I want to blow on so I can get an appropriate reading?

If any of you experts happen to stumble upon this thread, please chime in. I need to get this thing running before I move to Wichita State for college in mid-August, just about two or three weeks away. I'd like to do more than just throw parts at this car and hope it fixes it.

[CRE]

The TPS and/or AFM can present skewed signals due to excessive wear. They can also wear out to the point that as the sensor is moved the voltage output is not a smooth, steady change but one with pits and spikes.

The hairdryer thing was something I had to do to finially find the cause of a problem I was having some time ago when my AFM died. I was having a very bad stutter (some might have thought it felt like a miss) and if the car was running up to temp it would just bog and try to die when you applied throttle.

[Chris R]

I ordered a new AFM and put that on today. The stuttering once it heats up has done away. It's now drivable. But, under acceleration, while the motor revs is still seems like the car is hesitating until it gets above 3000k.

And there is a misfire at idle. The car will sometimes feel like it's misfiring (very hard to notice) under acceleration.

To recap what we've done with it:
New Distributor cap (they sent us the wrong rotor, the one on the car is circular)
New TPS
New AFM
Checked spark plugs, they're in decent condition and fine
Cleaned the galley of oil and replaced the gaskets.


This is a JDM cressida motor, but the previous owner said he had put the Supra throttle body back on. There were two throttle bodies that came with the car, the one on it and the extra he gave us. The new CPS would one work with the extra, and the old one would only work with the car that came on the motor. Currently the new CPS-throttle-body is on the car.

All the parts I've ordered have come from Rock auto parts. They list two engines, the 7MGE L6 FI and the 7MGE L6 MFI. I've been choosing FI. I figured it stood for fuel injected, not sure about MFI, searching warranted no results.

The car is running better, but I still think it could be running stronger. Any ideas? We plan to change out the ECU and check the timing tonight.

[AJ'S 88NA]

Don't remember and you didn't list if you've set the timing?

[Chris R]

Don't remember and you didn't list if you've set the timing?

Actually no, we haven't checked it with a light yet. Thanks.

Btw, I checked all the vacuum lines, they look good to me.

[AJ'S 88NA]

Actually no, we haven't checked it with a light yet. Thanks.

Btw, I checked all the vacuum lines, they look good to me.

Yes you need to check it and with the jumper wire per TSRM. 10 deg BTDC is stock, you can bump it up a little, will help your low end.

[Chris R]

Yes you need to check it and with the jumper wire per TSRM. 10 deg BTDC is stock, you can bump it up a little, will help your low end.

We set the timing at 10 Deg. We jumped it too (you put it in diagnostic mode, correct?). Still misfiring under idle and acceleration.

[AJ'S 88NA]

We set the timing at 10 Deg. We jumped it too (you put it in diagnostic mode, correct?). Still misfiring under idle and acceleration.
I see you said you checked the plugs, did you gap them? Also how old are your plug wires?

[Chris R]

I see you said you checked the plugs, did you gap them? Also how old are your plug wires?

Gaps are fine. Plug wires should be as new as the plugs, but I'm not 100 percent sure. That's next on my list, aside from the O2 sensor.

[AJ'S 88NA]

Don't think the 0-2 sensor would give you the problems you have. Have you checked the ISC? There's checks in the TSRM on that and it does need cleaned sometimes. Are you sure you have the TPS calibrated right? It also could cause the problems you describe.

[Chris R]

Don't think the 0-2 sensor would give you the problems you have. Have you checked the ISC? There's checks in the TSRM on that and it does need cleaned sometimes. Are you sure you have the TPS calibrated right? It also could cause the problems you describe.

Neg on the ISC. What is that?


When I adjusted the tps, I hooked up a voltmeter and turned it until it deflected it (analog meter) and then turned it back just a hair. I honestly can't remember if I gapped the lever and the stop screw or not, but I remember someone (Jetjock, I think) saying that it didn't really make a difference if you gapped that.

[AJ'S 88NA]

ISC idle speed control. CSI cold start injector, another possiblity that you should check.

[Chris R]

ISC idle speed control. CSI cold start injector, another possiblity that you should check.

Okay. I'll search for those, thanks.

How about the fuel pump or filter? Or the fuel pressure regulator?

I've also got a three inch exhaust, custom headers super dragger muffler (From the previous owner, haven't replaced it yet)

The throttle is weird, it's I have to floor it to really get it going. It'll accelerate at 50% or 70%, but above 2.5k only slightly, and sometimes not at all. Below 2.5k it misses pretty hard sometimes on acceleration. Once it gets up to 3.5k it kicks in pretty hard.

[Chris R]

Every now and then when you crank it, it'll idle very roughly and just keep going lower until it dies. If you try to accelerate it, it'll drive but with a huge miss for about 5 miles and then it'll slowly return to normal.

It usually cranks alright, so I really don't see that problem being the CSI or ISC.

And if its not plug wires, then I'm guessing its fuel related? Filter? Pump? Relay? Or Injectors? Hell, those are all pretty expensive.

To really get a response from the car I have to push it all the way to the floor. I'm kind of lost here guys, I've tried to test everything but it feels like I'm starting to just throw parts at the car and hope something works.

[Chris R]

Another update here. I threw some MSD plug wires on there. It helped a bit, but there's still a lot of missing. Finally convinced my dad to drive it, and this is what he noticed:

Under 3200 (or so) rpms, the car misses pretty bad, still kind of a sputter. At the really low rpms (2000 and below) it misses really bad.

Every now and then, when you start the car at an idle, it will idle very rough, lobing and hunting. From the smell the car was giving off, he proposed that it must be running pretty rich. We plan to replace the O2 sensor tonight, but we think that there might be more involved here.

I noticed that my injectors are yellow tipped, and thus I'm guessing they are the low impedance ones. But that I may be missing the injector resistance pack. There's some blank screw holes right above the drivers side strut tower, with nothing there. Would a missing resistance pack cause any of these symptoms, or simply burn up the injectors over a period of time?

I'm looking at trying to bypass the relay for the fuel pump to see if its a bad relay. Come to think of it, if fuel pressure may be the culprit, could be fuel pump be stuck on "high" and be dumping too much fuel into the motor at the lower rpms? I don't know if the switch from running like shit to completely smooth would be instantaneous though.

Above 3200 rpms, the engine smooths out, pulls like hell, and barely misses.

In 1st, 2nd, and 3rd gears it pulls alright throughout the rpm ranges. In 4th and 5th, you really have to floor it to get a proper response from the car. Once the ACIS kicks in, or whatever is helping it out, it responds pretty well.

The hunting idle seems to be the worst after the car has warmed up. When the car starts cold, it misfires, but the motor does not have a lobe/hunt to it. We have replaced the AFM.

So either it's not getting adequate fuel, or something is causing the thing to run stupidly rich, at least sometimes. again, any ideas guys?

-edit- Did a little bit more searching, could be fuel pressure? Guess we'll try and check that.

[Chris R]

Cleaned out the ISC yesterday. Guess we'll see what that does.

No ideas on what the cause of my problem could be? I'm trying to get a good idea here instead of just trying a relay, pump, switch and injectors at it.

Local mechanic said the problem could be valve guides.

[Chris R]

This is probably my last update as I haven't gotten a response in about six days.

I cleaned out the ISC. It seems to have helped a little bit. Before the loabing/hunting starts, the car idles a bit higher, but the misfire isn't as pronounced at first.

Spraying carb cleaner on the vacuum lines (recommended by a local mechanic) didn't do anything for the loabing once it started. But that isn't exactly a scientific test, so we'll try and hook up a vacuum test early next week and see where that gets us.

When testing out the cleaned ISC, I noticed that at first, even when the car warms up, you can run and restart it all you want. It'll idle about 1000 every now and then, and the misfire is prounounced, but for the most part it'll act alright.

But when you let the car set after it has warmed up for about 15-30 minutes, then the very rough idle, the loabing, the hunting will start. After that started, I shut the car off, left it for about 45 minutes again, and it cooled down a bit. But it the engine still did that rhythmic shudder/loab/hunting deal.

So after replacing, the AFM, the TPS, cleaning out the ISC, replacing the wires, checking the plugs, and checking for vacuum leaks I am completely lost as to what it could be. Bypassing the fuel pump did nothing by the way.

I really don't know how else to describe the problem guys, so I really don't know what else to say to garner further suggestions here. It feels like I'm wasting my time by continuing to update this thread on my progress, so I'm just gonna stop here.
I've search and I've searched, but I haven't found much to pertain to this specific problem.

If anyone feels the notion to respond, I have this thread subscribed so I'll get an e-mail when you respond. Same with PMs. Thanks for those that helped.

[CRE]

Hey sorry you're still having trouble. I haven't been on much lately and haven't really had the energy for the more involved threads (I figured I'd leave it to those with more energy and motivation).

Have you tested the distributor and igniter? Have you checked the voltage at Vf both when it's doing this and when it's fine? Have you checked all of the grounds in the engine bay?

[Chris R]

Hey sorry you're still having trouble. I haven't been on much lately and haven't really had the energy for the more involved threads (I figured I'd leave it to those with more energy and motivation).

Have you tested the distributor and igniter? Have you checked the voltage at Vf both when it's doing this and when it's fine? Have you checked all of the grounds in the engine bay?


Thanks for the response.

The distributor is odd. We ordered a cap and rotor for a 7mge supra, but the kid had kept the cressida distributor from before in there. So we have the proper rotor, but a USDM 7MGE cap on there. Both caps looked pretty similar, and the car ran better with the newer cap.

The voltage at Vf? I'm a little bit confused on that. I've been doing most of my testing for resistance, but that is just hooking up two connectors to the mutli-meter. By ignitor I'm guessing you mean the ignitor coil. Are you talking about the VF on the distributor cap?

I do know that when we checked the timing, and had one of the wires partially out of the distributor, it was putting out a hell of a spark. So we're thinking the coil is pretty healthy since it had no trouble with producing spark on the #1 wire.

Negative on the grounds, and I guess I didn't think about the ECU ground.

As a side note, could this be a symptom of a blown headgasket? Someone suggested a leakdown test, so I figured I'd ask.

[CRE]

It could definitely be indicative of a BHG... it's not a given, but it is quite possible.

The igniter is mounted below the ignition coil... look it up in the TSRM.

Vf is a feedback line where the ECU presents data regarding what it's doing, if codes are stored and so on... Look at the link below for more info:
http://www.supramania.com/forums/showthread.php?t=39856 Don't assume you know what's going on just from the result of that test. I can't remember if the Vf line is actually run to the diagnostic box in our car or if you have to read it at the ECU. If it is run to the diagnostic box you'll find it's location in the box here:
http://www.fadingworld.com/Supra/Electrical/Diagnostic%20Box%20Demystified/Diagnostic%20Box%20Demystified.html

How is the distributor "odd"? Be specific and post pics if you can.

By the way, carb cleaner works quite well for locating vacuum leaks. I prefer using propane myself, but either will do the trick... Personally, I've had better luck with propane.

[CRE]

Oh, and I know you've checked the ignition advance timing, but have you physically checked the timing? You know, made sure that when the crank is at 0º (TDC) that the cam gears are and that the distributor's drive gear is also lined up right.

Good spark from one plug wire at idle doesn't rule out much of anything either. You could still have a distributor problem or an issue with the igniter.

[AJ'S 88NA]

Check and clean your cold start injector?http://cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&P=77

[CRE]

The cold start injector is only powered WHILE you're cranking the engine... if it fails you may have difficulty starting, but that's really about it. If it's leaking you may run rich, which the ECU would trim for as much as possible, but the cylinders may see varying amounts of fuel from one another.


when you let the car set after it has warmed up for about 15-30 minutes, then the very rough idle, the loabing, the hunting will start. After that started, I shut the car off, left it for about 45 minutes again, and it cooled down a bit. But it the engine still did that rhythmic shudder/loab/hunting deal.

This has my interest. Test the ECU coolant temp sensor when the engine's cold and when the coolant system is up to temp. See if the resistance is pretty steady or if it fluctuates.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=FI&P=113

You could also try taking a resister with a value of, oh, 470Ω or 680Ω and plug that into the ECU's water temp sensor's harness connector. This will let you see how the ECU's behaving when you know you're getting a solid temp reading that's in the normal "warm" range. I think even 1KΩ would be fine for this.

[Chris R]

It could definitely be indicative of a BHG... it's not a given, but it is quite possible.[quote]

I hope not.


[quote]
The igniter is mounted below the ignition coil... look it up in the TSRM.

Alright.



Vf is a feedback line where the ECU presents data regarding what it's doing, if codes are stored and so on... Look at the link below for more info:
http://www.supramania.com/forums/showthread.php?t=39856 Don't assume you know what's going on just from the result of that test. I can't remember if the Vf line is actually run to the diagnostic box in our car or if you have to read it at the ECU. If it is run to the diagnostic box you'll find it's location in the box here:
http://www.fadingworld.com/Supra/Electrical/Diagnostic%20Box%20Demystified/Diagnostic%20Box%20Demystified.html

Ah, okay, I understand now. In that link that shows the diag box, it has a VF1 connector. It says to link it to E1 for TCCS Fuel Trim feedback. That sounds the right lead.



How is the distributor "odd"? Be specific and post pics if you can.

It's just got a USDM cap (looks the same as my old one) with a Cressida rotor. I'm thinking that despite the rotor difference between the Cressida and the USDM 7MGE, the caps are the same.



By the way, carb cleaner works quite well for locating vacuum leaks. I prefer using propane myself, but either will do the trick... Personally, I've had better luck with propane.

Would spaying it on the head gasket give any indication what so ever of a leak opening up there under those certain conditions?


Check and clean your cold start injector?

I'll definitely check that tomorrow. The only reason I had discounted that is because it seemed like the car didn't have much trouble starting. But it's worth it to know either way.


This has my interest. Test the ECU coolant temp sensor when the engine's cold and when the coolant system is up to temp. See if the resistance is pretty steady or if it fluctuates.

Okay. Could this be causing the engine to be overly rich once it warms up and then sets?


You could also try taking a resister with a value of, oh, 470Ω or 680Ω and plug that into the ECU's water temp sensor's harness connector. This will let you see how the ECU's behaving when you know you're getting a solid temp reading that's in the normal "warm" range. I think even 1KΩ would be fine for this.

So I could hook up a resister to the harness, kind of like I would hook up a mutli-meter? And then see how the engine (ECU, really) reacts?

[CRE]

Ah, okay, I understand now. In that link that shows the diag box, it has a VF1 connector. It says to link it to E1 for TCCS Fuel Trim feedback. That sounds the right lead.

Whoa.... you put a multimeter to it. The positive lead connects to Vf1 and the negative connects to E1. Do NOT jumper the two, you could damage the ECU... you may have meant that, but the word "link" makes me think of a jumper. That'd be bad.

Just buy a new rotor, they're very inexpensive. sheesh.

No, propane or carb cleaner will probably not help diagnose a BHG... none that i can think of anyway.

A faulty temp sensor can cause enrichment and timing issues. So, you unplug it and then insert one wire from each side of the right size resistor into each of the two holes in the connector on the harness. This will make the ECU think the coolant is at a certain temp and not changing... it'll at least help knock out one possibility. Put in the resistor BEFORE starting the car and make sure the harness can't swing into the fan.... watch them fingers. ;)

[Chris R]

Whoa.... you put a multimeter to it. The positive lead connects to Vf1 and the negative connects to E1. Do NOT jumper the two, you could damage the ECU... you may have meant that, but the word "link" makes me think of a jumper. That'd be bad.

Yep, that's what I meant, just using a mutlimeter to read the voltage when it's normal and when it's loabing. No jumpers, haha.


Just buy a new rotor, they're very inexpensive. sheesh.

We did. It's just got a USDM 7MGE dist cap on it, as opposed to a JDM Cressida 7MGE dist cap. I'm just saying that despite the rotor difference, I don't think there's any differences between the Supra cap and the Cressida cap. The rotor is new.


No, propane or carb cleaner will probably not help diagnose a BHG... none that i can think of anyway.

Alright, thanks.



A faulty temp sensor can cause enrichment and timing issues. So, you unplug it and then insert one wire from each side of the right size resistor into each of the two holes in the connector on the harness. This will make the ECU think the coolant is at a certain temp and not changing... it'll at least help knock out one possibility. Put in the resistor BEFORE starting the car and make sure the harness can't swing into the fan.... watch them fingers. ;)

Gotcha. That's worth a shot then. I have to head up to Wichita on monday, so I can grab some resistors.

It's raining out, so I haven't gone out to test the CSI,Coolant temp sensor, or the VF, with the multi-meter yet. But I'll come back here and give the voltages to you guys when I do later on today.

[jetjock]

No resistors needed. Simply unplug it...

[Chris R]

Alright, here's what I got on the Water Temp Sensor. I used two alligator clips so I could keep the multi-meter plugged into the sensor without having to hold it. But one wire was a slightly larger than the other. Does this matter when measuring resistance, or are my results skewed?


It reads 1.2k ohms just sitting there.

On an idle, it goes down to .08k.

Idle gets a bit rougher as it heads down to .06k

After a couple minutes the resistance has moved down to .04k

On the first mark on the temp gauge (the bold one) the resistance was about .02k

At the third mark, barely above .02k

5th Mark, just below .02k

6th mark, a little bit above .01k

Between the six and seventh marks it reads exactly .01k. This is where the gauge usually reads once it has warmed up.

A little bit later, still between the sixth and seventh marks, it went down to .01k


Hope that's not too much information overload.

I noticed that the car would not start when I unplugged the water temp sensor. I had to plug it in, start it, unplug it and then get my readings.

This time, it started hunting without having to warm up and sit. Once we plugged the sensor back in after the car had fully warmed up, the engine smoothed out a bit.


Btw, I think the cold start injector is fubar'd. The resistance didn't measure right, it was barely registering. We have an extra from the old motor. I'm going to test the resistance on that and throw it on the car, see if that does anything.

[jetjock]

What you saw is normal. The engine will be hard starting (at least when cold) without the coolant sensor because unplugging it makes the ECU think the coolant is hot. If it thinks it's hot it won't supply the extra fuel needed for cold start and warm up enrichment.

Btw a quick check shows that's an interesting town you live in. Dorothy and Toto would be proud ;)

[Chris R]

What you saw is normal. The engine will be hard starting (at least when cold) without the coolant sensor because unplugging it makes the ECU think the coolant is hot. If it thinks it's hot it won't supply the extra fuel needed for cold start and warm up enrichment.

So the resistance readings are normal? I tried my best to compare it to the chart in the TSRM, but it's hard given that the temp gauge gives absolutely no indication as to what the actual temperature is. How the rougher idle when the sensor is unplugged?


Btw a quick check shows that's an interesting town you live in. Dorothy and Toto would be proud ;)

Heh, probably so. My parents, both Army retirees, settled in this town after my mom left the Army with 27 years of service in 2007. I stay here over the summers.


I'm thinking that I'm dealing with a two-part problem here. I drove it to church, and had planned to take it out on the highway to see if the ECU threw any other codes than the code 43 (starter) it has been throwing.

I never got the chance to do that, as we had an incoming hail-storm, so the Supra went safely under the barn. But it acted ridiculously sluggish. In 1st gear it would rev, but it would mis. In second it would rev, but at about 2.5k the engine would start missing like crazy. It did this every time in second gear for about a mile. After that I took it out on the highway and it behaved itself a little bit better. When I started the engine up to get to church in the first place, the car ran flawlessly. Barely missing, if at all. I'm waiting to get that fuel pressure test done on Monday or Tuesday. I think that'll be telling. That and the compression (and hopefully a leakdown, if the guy has it) test.

I can still smell a sweet smell outside the car, but my dad or I really can't tell if its coolant or gas from running rich. Its hard to tell if we've burned any coolant, we've spilled so much taking the throttle body on and off, heh.

[A-model_]

While reading on a mr2 forum I found a thread that described the problem you were having.

" is my ecu dieing? car bogging out
I turn the car on after sitting lets say over night and it runs fine, will go into the upper rpm range no problem. Then after maybe 10 minutes or so of driving, it bogs and doesn't want to move past 4k rpm and then just bogs completely to where I'm sputtering when I push the gas at all but it will idle just fine.

Then If I turn the car off and let it sit for a while, it will run fine for a few minutes then start bogging again. Man it is frustrating!!

any ideas? could my ecu be crapping out and it sort of resets itself after being off for a bit?"

Turned out to be the coil.

"ok, just for future reference, I changed out my ignition coil and have driven it about 100 miles or so and it hasn't hesitated at all so that should be a good fix!

My old coil was an accel universal coil, looked a bit old so out with the old and in with the new.

Thank a bunch papo J and everyone for your help."

Some thing to think about in case you have checked everything.

[Chris R]

While reading on a mr2 forum I found a thread that described the problem you were having.

" is my ecu dieing? car bogging out
I turn the car on after sitting lets say over night and it runs fine, will go into the upper rpm range no problem. Then after maybe 10 minutes or so of driving, it bogs and doesn't want to move past 4k rpm and then just bogs completely to where I'm sputtering when I push the gas at all but it will idle just fine.

Then If I turn the car off and let it sit for a while, it will run fine for a few minutes then start bogging again. Man it is frustrating!!

any ideas? could my ecu be crapping out and it sort of resets itself after being off for a bit?"

Turned out to be the coil.

"ok, just for future reference, I changed out my ignition coil and have driven it about 100 miles or so and it hasn't hesitated at all so that should be a good fix!

My old coil was an accel universal coil, looked a bit old so out with the old and in with the new.

Thank a bunch papo J and everyone for your help."

Some thing to think about in case you have checked everything.

I was searching for testing the ignitor in the TSRM earlier and also read up on how to test the coil. So that's definitely on my to do list. Thanks man.

[Chris R]

I'm not sure if my distributor is fubar'd or not. When I hook the mutlimeter up to it, I get almost no reading. I changed the batteries, made sure it is zeroed, but got almost nothing when I tried to read for 10 ohms and 1k ohms.

I hooked the multi-meter up to the temp sensor, and it read about 1k ohms, though when I just let it set there the mutli-meter deflected after a minute or so. It's about 74 degrees outside (I'm guessing that'd be the temperature of the sensor at the moment.)

Has that happened to anyone? I might need to source another mutli-meter here. This one is pretty old.

[Chris R]

Good update here. Digital mutli-meters for the win.

Alright, the old multi-meter was bad. The new digital one from Lowes said that it checked out on all connections. Good.


Next up was the coil pack. I couldn't get the connector off, so I had to punch through the wires (I know, I know :3d_frown:). The resistance jumped from .2 to .3, which is in range, but it also spiked to .4, which is not in range. I wasn't sure if that was just a bad connection because I had to jump the wires, or the coil is going out.

I went back and adjusted the TPS with the new meter. Haven't checked out the CSI again, or the water temp sensor, but those are next. I should also be able to check the VF signal much easier now.

The check engine line didn't pop up when I took it out for a drive, so that's a good thing. Initially, I had forgotten to plug the TPS in :nono:, but when I plugged it back in the idle dropped from 1200 down to 700 and got a little bit rougher. The acceleration characteristics changed, but I got a better picture of what it's doing. Under 2900, it misfires, and lags, but isn't terrible. Between 2900 and 3400 it sputters, and runs like utter shit. Hit 3500 and all is cured, the car runs jumps (literally) to life and pulls fine. Sometimes these numbers vary by a couple hundred rpms.

The local mechanic never got with us, so I'm going to have to check and see if the local o riley's or autzones rent out fuel pressure and vacuum kits for reading the corresponding pressures. If not, it'll take me a bit longer as I'll just have to cough up the money for the kits, and money is in rather short supply right now.

So what do you guys think? My problem does sound similar to what the MR2 owner in A-model's post described. But mostly the part about how the car will get worse as it warms up, and how the motor clears up in the high rpms.

According to the TSRM (http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=IG&P=5), the igniter is the last thing on the list to replace in the ignition department (coil comes first, we've already replaced the ECU). It really doesn't give any way to check the resistance, so I'm kind of stuck for now until I know for sure the coil pack and distributor check out 100 percent. And ... I still haven't went out and checked each ground either, though I have the TSRM page on it bookmarked. There's only so much time in a day, and there's quite a bit of things on this car to check to solve a misfire, heh.

I'm not really sure it could be a fuel pump issue, except for the relay. I would think that if it was the pump itself, or a clogged filter, or dirty injectors, the motor would not liven up at the top end once it hits the powerband. It would be a crappy run all the way through. I am thinking the relay may be suspect though, because if it isn't switching from low to high properly then that could cause problems at the low end.

A headgasket, well, again, I don't know for sure. I'm thinking that if it was a crack, then it would only get worse as the motor cooled because the gasket expands as it heats up, possibly sealing the crack. But headgaskets are a complicated issue that I don't fully understand.

[jetjock]

All you have to do to eliminate the relay is drive the car with B and FP in the diag block jumpered. That'll bypass it. A bad relay will also show up as a dip in fuel pressure during a snap throttle test. I doubt that's your problem but I have seen them go bad. On a turbo it shows up at about 3 psi of boost. On an NA I don't know.

[Chris R]

All you have to do to eliminate the relay is drive the car with B and FP in the diag block jumpered. That'll bypass it. A bad relay will also show up as a dip in fuel pressure during a snap throttle test. I doubt that's your problem but I have seen them go bad. On a turbo it shows up at about 3 psi of boost. On an NA I don't know.


The kid who owned it before hand installed a switch next to the cruise control in the dash that bypassed or 'primed' (that's what I remember him saying) it. When switched on it makes the same buzzing sound out of the relay that jumping B and FP does. The switch isn't a toggle (it doesn't say in the 'on' position), and he said he only used it at start up.

If I could guess, I would say that bypassing the relay just throws the pump into "high," so that the engine has more than enough fuel for whatever rpm it's at. But I really don't think I'm understanding the entire concept behind the relay.

[jetjock]

The relay shunts a resistor that's inline with the pump. The circuit is fail safe in that this happens when the relay turns off, not on. Put another way the ECU normally keeps the relay turned on, only turning it off for high pump speed during cranking and when the engine needs more fuel at higher load.

Unplugging and jumpering the resistor is another way to bypass it but the method still leaves the relay in the circuit. The relay shouldn't buzz when jumpering +B and FP. I hope it's not buzzing with the engine running. If it does you need to fix it before doing anything else.

It *will* buzz with the key off if another +12 volt source is used instead of +B to power it. Sounds like that's what the PO did. Again, you really ought to fix these kinds of things first but for now just jump the resistor at it's connector to run the pump at high speed. You can bypass the relay by unplugging and shorting the two big contacts in it's connector together. If things improve you can go from there.

[Chris R]

The relay shunts a resistor that's inline with the pump. The circuit is fail safe in that this happens when the relay turns off, not on. Put another way the ECU normally keeps the relay turned on, only turning it off for high pump speed during cranking and when the engine needs more fuel at higher load.

Gotcha. I think I understand it now.



Unplugging and jumpering the resistor is another way to bypass it but the method still leaves the relay in the circuit. The relay shouldn't buzz when jumpering +B and FP. I hope it's not buzzing with the engine running. If it does you need to fix it before doing anything else.

That's something I'll check for today.



It *will* buzz with the key off if another +12 volt source is used instead of +B to power it. Sounds like that's what the PO did. Again, you really ought to fix these kinds of things first but for now just jump the resistor at it's connector to run the pump at high speed. You can bypass the relay by unplugging and shorting the two big contacts in it's connector together. If things improve you can go from there.

The key has to be on for the switch to do it's job. So the switch would turn off the relay, which turns off the resistor, thus allowing the pump to go into high output mode, which gives the motor more fuel at startup and high load.

A relay isn't that expensive (11 something from rockauto parts) and I don't want to go around with a paper clip in my diag box, or alligator clips on my fuel pump connector, heh. So I'm not thinking of this as a 'fix,' just as a way to see if this is my problem.

[CRE]

Disconnect the Round yellow connector with 4 wires running to it from the resistor/relay. Jumper the Blue w/ black stripe wire and the Black w/ red stripe wire. This will bypass both resistor and relay.

Didn't we already do this?

[Chris R]

Disconnect the Round yellow connector with 4 wires running to it from the resistor/relay. Jumper the Blue w/ black stripe wire and the Black w/ red stripe wire. This will bypass both resistor and relay.

Didn't we already do this?


I think I got focused on something else, but I went and did it today. I jumped the B+ and FP connections, as shown here in Shaeff's diagram. (http://www.supramania.com/forums/attachment.php?attachmentid=3419&d=1133646982)

I think that's what jetjock was talking about. Today was the first day I went out and drove the car with it jumpered. The engine smoothed out quite a bit. It seemed like it regained a lot of power, and the transition from the low end to the high was smoother. I didn't notice any of the bogging, even between 2900 an 3400 RPMs.

But today I only drove it about 30 miles. On Friday I've got some stuff to do for work, and a haircut to get so I'll be doing about 70 miles of driving. Yeah, Dorthy and Toto would be proud of how remote this town seems, especially if they have stock in gas companies. But anyways, I don't think I'll be entirely convinced that the bogging problem is solved until after I see how it acts Friday.

It's still throwing a code during driving, so later tonight I'm going to go check that out.

Also, the idle is still a little bit rough. What it does is that if I let it idle for a bit, the rpms will just go slowly decrease and the hunting will get worse as it goes down. It usually idles about 900, but once it gets down to about 650 it is like it's hunting or a 'sucking' idle.

The engine still lopes and shudders (loab, lope, eh, same difference in my engrish) after I warm it up and let it set.

But, on the plus side, before, after it started loping the engine would run like utter crap for about 10 miles. Now it seems to pick right up as soon as I drive off.

So I still have to figure out what is throwing that code and what is causing the rough idle, but the car, at least for now, seems to drive a lot smoother. So I'm going to go ahead and order a relay and coil pack (just in case, the resistance didn't check out just right) tonight and see what that does.

[CRE]

I think I got focused on something else, but I went and did it today. I jumped the B+ and FP connections, as shown here in Shaeff's diagram. (http://www.supramania.com/forums/attachment.php?attachmentid=3419&d=1133646982)

Yeah, that's what I was referring to as well. I was thinking that at the Diagnostic box FP might not bypass the resistor and relay, but it does, so either location would have been fine.

[Chris R]

Yeah, that's what I was referring to as well. I was thinking that at the Diagnostic box FP might not bypass the resistor and relay, but it does, so either location would have been fine.

Well, I noticed that when I jumped the connections at the diag box, the relay buzzed. Same as when I used the switch.

But when I jumpered the connection at the relay box connection, the relay made no sound. But there was an obvious difference in driving. I haven't test driven it with the diag box jumpered. I just used a paperclip on both, since this was only for a test and not a permanent fix.

[CRE]

It may be worth testing to see how much power is making it to the relay from the battery.

[Chris R]

It may be worth testing to see how much power is making it to the relay from the battery.

Good idea, I'll check that out. Just to be sure, should I be worried that no noise was made when I jumped B+ and FP at the connection? I wouldn't think so, since it seemed like the point was to bypass the entire assembly altogether.

[CRE]

No, if you had the relay disconnected it stands to reason it wouldn't make any noise. ;)

Oh, and have you checked to see where the hell that switch is wired?


EDIT: Actually, the lack of noise at that point helped reassure us as to the source of the buzzing. :D

[Chris R]

No, if you had the relay disconnected it stands to reason it wouldn't make any noise. ;)


Haha, common sense told me that, but sometimes it's better just to ask. Especially when it comes to electrical.



Oh, and have you checked to see where the hell that switch is wired?

I've tried poking around under the dash, and checking on the other side of the firewall, but I honestly couldn't find the two wires he used, which were red and yellow (didn't notice if they had stripes on them or not).

There's nothing strange or out of place that I can see running to either the relay or the diag box, so I'm guessing he split into the wires further back in the engine. Probably just to keep the bay clean.



EDIT: Actually, the lack of noise at that point helped reassure us as to the source of the buzzing. :D

If the car did start randomly buzzing at me, or self destructed for that matter, I can't say I'd be all that surprised.

[CRE]

Haha, common sense told me that, but sometimes it's better just to ask. Especially when it comes to electrical.

It's ok... nothing wrong with trying to be sure.


I've tried poking around under the dash, and checking on the other side of the firewall, but I honestly couldn't find the two wires he used, which were red and yellow (didn't notice if they had stripes on them or not).

There's nothing strange or out of place that I can see running to either the relay or the diag box, so I'm guessing he split into the wires further back in the engine. Probably just to keep the bay clean.

Haven't tried using a multimeter to track it? How precisely does this switch effect things?

Never guess about someone else's custom wiring... it'll bite you in the ass.


If the car did start randomly buzzing at me, or self destructed for that matter, I can't say I'd be all that surprised.

Neither would I. ;)

[Chris R]

Haven't tried using a multimeter to track it? How precisely does this switch effect things?





I honestly wouldn't know how to track it with a mutlimeter. The switch makes the relay buzz, and it helped the car to start up a bit easier on a cold start. I ever flipped it on while I was driving the car, so I can't say what happened there. The switch burned out not too long ago though, though I really can't see that as the cause since the switch was only used at start up and that's it. As I said, it wasn't an "on and off" switch that stayed in the on position. It just reverted back to the off position as soon as you let go of it.



Never guess about someone else's custom wiring... it'll bite you in the ass.

Good point.

[CRE]

Well, does the switch need to be in one position or another to start the car?

One side of the switch is going to supply either 12v or a ground. I'd try that first, then knowing which you'll know the next place to check. If it turns the pump on without the key in the ignition then it's supplying 12v somewhere after the relay.

Have you checked to see what error code is stored or did I miss it?

[Chris R]

Well, does the switch need to be in one position or another to start the car?

To start the car at all? Nah. The car starts (or tries too anyways) regardless of what position the switch is in. You see, I'm not entirely sure of the reason why the PO put the switch on. I asked him before I bought it, and he mentioned something about priming the pump, but the specific reason escapes me. I'm thinking it was to help give the fuel pump a "boost" on a cold start, or something along those lines.



One side of the switch is going to supply either 12v or a ground. I'd try that first, then knowing which you'll know the next place to check. If it turns the pump on without the key in the ignition then it's supplying 12v somewhere after the relay.

The key has to be in the ignition, if I recall. And it has to be in the on position. I'm pretty sure on this, but I haven't used it in awhile.


Have you checked to see what error code is stored or did I miss it?

I had cleared the codes, but then went and drove without the TPS plugged in, on accident . So that might of thrown a code, but no check engine light showed up while I was driving, or after I plugged the TPS back in and restarted the car.

Today it threw a code on the highway, like it usually does after about 15 minutes of straight driving on the highway. Sometimes the engine light turns off, sometimes not. Guess it depends on the mood of the car at that given time.

Previously it was throwing a 21 (O2 sensor) and a 43 (starter). The starter doesn't seem to be giving me any problems, though sometimes it can be a bit of a pain to start. That could be the CSI though. I need to go out and test the resistance on that when I check for codes tomorrow. I'm not sure if anything else would cause the ECU to throw a code 43 other than a starter going bad. I know the coil belongs to another code, but could problems with that cause the ECU to throw a 43?

As for the code 21, we replaced the O2 sensor and cleared the computer. As I said, it threw a code earlier today on the highway, but I haven't went out and checked what it was yet. It's in my plans for tomorrow. I think it'll be interesting to see if it keeps throwing a 21, or picked something else up. I'm kind of thinking it'll be another 21, but we''ll see.

[CRE]

You can get a code 43 from just pop/push starting the car. I don't remember the implications of this happening, perhaps JJ will remind me? (HINT ;) )

It's been said that a bad O2 sensor would effect your mileage but nothing else... Although, I'm not so sure that would be the case. What if it's just skewed enough that the ECU thinks it needs to add a lot more fuel or pull more than is really called for?

I'd fix the o2 sensor, test the STA pin at the ECU for 12v when the engine is being cranked and find out what code is being stored... all obvious stuff.

[Chris R]

You can get a code 43 from just pop/push starting the car. I don't remember the implications of this happening, perhaps JJ will remind me? (HINT ;) )

If I did, which I may have, it's because I was on a hill with nothing better to do. Boredom gets to people sometimes, heh.



It's been said that a bad O2 sensor would effect your mileage but nothing else... Although, I'm not so sure that would be the case. What if it's just skewed enough that the ECU thinks it needs to add a lot more fuel or pull more than is really called for?


Right. I've read that something else in the air flow management system can push the car into thinking that it's the O2 sensor at fault. This could be from something causing the car to run rich, or maybe even lean. Though, I smell quite a bit of fuel. So either it's coolant (:3d_frown:) or the car just runs ridiculously rich at some points. I'm thinking it's just running rich, but I don't want to just take a wild guess and blow a hole through my pistons.



I'd fix the o2 sensor, test the STA pin at the ECU for 12v when the engine is being cranked and find out what code is being stored... all obvious stuff.

Sounds good. I'll check it out and get back to you.

Btw man, you must have a late night job, or get just as bored between semesters as I do.

[Chris R]

I checked the codes, 21, 22, and 43.

22 is the water temp sensor, and I'm thinking that the water temp sensor is just stored from the other day when I had it unplugged.

So it's still throwing a 21, even though we've replaced the O2 sensor. I'll get out there and check the wire going to the ECU, and make sure the wire from the O2 sensor hasn't burned up because of the headers.


btw - I ordered the relay, but it won't be arriving until one day after I leave for college. Gotta love the four day shipping times for their two day shipping. Luckily I'll only be about 90 miles away, so I can still get my hands on the relay sometime later in the week. Will driving with the B+ and FP wires jumped at the relay connection be an issue for a week? I'd rather not burn my pump up.

[Chris R]

You guys probably so this coming. Rockautoparts.com didn't send me the correct relay, so I had to keep on driving with it jumpered at the relay connection, completely bypassing the relay altogether. I drove it like this for about a week.

I was driving earlier today and the car just revved down, and then died. When I try to start it, it's like the starter almost gets it going, but it just won't start. Hard to explain, but it seems to me like the car is not getting fuel.

My best guess is that the fuel pump was not designed to run on 12v constantly, so with no relay the fuel pump blew, or the fuse. When I jump Fp and B+ using the wires that came into that switch the PO set up, I can hear a whir in the back, which has to be the fuel pump. Jumping those two wires had the same effect of jumping the FP and B+ connections at the diag box, where the relay would sound. Jumping those two connections at the relay connectors did not make the relay sound, obviously.

But with all the relay connectors hooked back up like normal, I hear a whir coming from the rear of the car. I don't hear any sound coming out of the relay up in the engine bay, despite it being connected.

I haven't checked the fuse, when I called toyota they told me it was either in the drivers side kick panel or the engine bay fuse box, but I had checked those before and didn't see anything relating to a fuel pump fuse. All the fuses I checked in the engine bay box looked fine.

Despite the whir in the back when FP and B+ are jumpered at the PO's switch it the dash, I'm still guessing either the pump is gone, or the fuse blew. I'm going to recharge the battery tomorrow for the hell of it and see if it starts. Pumping the gas doesn't do anything, but it does seem to help when you jump the FP and B+ connections at the PO's switch.

[jetjock]

Your best guesses pretty much suck ;)

Pumping the pedal when cranking does absolutely nothing in a fuel injected car. Holding it to the floor is another story but we won't get into that.

Fuel pump gets it's power through the EFI fuse both during normal operation and when using FP to run it. If the EFI fuse was blown you'd have a lot more issues. Nor would you hear the pump.

What happened to you getting a fuel pressure gage? Be handy right about now. There are several ways to check the pump. 1) Look at the screw on top of the pulsation damper. 2) Crack the CSI line. 3) Set your meter to current and use it in place of the jumper.

Too bad you don't have a scope. With it could tell everything about the pump's health including what rpm it's running at and do it all from those two terminals in the diag block. I doubt your problem is fuel pump related though. Fuel related perhaps, but not pump related.

I'm not surprised you received the wrong relay...the quoted price seems cheap. Btw did the original problem disappear during the week you drove with the jumper?

[Chris R]

Your best guesses pretty much suck ;)

Haha, not surprising.



Pumping the pedal when cranking does absolutely nothing in a fuel injected car. Holding it to the floor is another story but we won't get into that.

Understood.



Fuel pump gets it's power through the EFI fuse both during normal operation and when using FP to run it. If the EFI fuse was blown you'd have a lot more issues. Nor would you hear the pump.

I thought that fuse would have something to do with it, simply because it was the only one that had anything to do with fuel. But it checked out, and there have been no other, newer, issues.



What happened to you getting a fuel pressure gage? Be handy right about now. There are several ways to check the pump. 1) Look at the screw on top of the pulsation damper. 2) Crack the CSI line. 3) Set your meter to current and use it in place of the jumper.


I think now that I'm schooling in Wichita, I'll be able to rent one. Our local mechanic bailed on us, and never got back to our repeated calls. We gave up.

But I can do the meter tomorrow.



Too bad you don't have a scope. With it could tell everything about the pump's health including what rpm it's running at and do it all from those two terminals in the diag block. I doubt your problem is fuel pump related though. Fuel related perhaps, but not pump related.




I'm not surprised you received the wrong relay...the quoted price seems cheap. Btw did the original problem disappear during the week you drove with the jumper?

The original problem half-disappeared. The loabing idle was still there, especially after the car warms up. But aside from that, the bad misfiring, sputter, low end torque loss, lack of throttle response and so on went away as soon as I jumpered that connection. Even the ACIS system smoothed out quite a bit. No huge jump at 3500-3800. I think the misfire returned today, but at the lower rpms.

What price should I be looking for? It's a Cressida 7MGE motor, JDM. And I'm not sure which of the parts in the engine bay he left alone and which ones he replaced. I've tried to contact him to get some idea, but I guess I already used up my one question when I asked him about the throttle body and something else. And nope, heh, it was no where near as bad as I am with you guys. But eh, I guessing since I've bought the car it is now my sole responsibility to reverse-engineer his stupid mistakes. And that's on top of the ones I make!