Engine hesitation and miss. New engine

[funky_monkey58]

Well first off I searched and then searched again, to no prevail.

My car is an 87 turbo and the mods that would be of importance to the issue at hand are rc 550s lexus afm fuel elbow delete walbro pump.

The issue is when I start the car it starts great first turn type of ordeal. But If I open the throttle even a little bit it bogs down and dies, much like pulling air from somewhere.

Now if I unplug my afm it will rev a little bit but when boost comes in it pops a bit and likes to backfire. but will remain running.

The afrs arnt too bad from what I was whatching between 11-14

Im at a slight loss as to what is going on in there. My timing is at 10 degrees with the jumper. my ecu isnt sending me any readable codes. And also I dont know if this is all that important but the tach isnt working either.

All in all its kinda a pain in my but at the moment any help or suggestions are highly appreciated. I have plenty of rescources to check systems but am at a loss as to where to check. As all the electronics ran perfect last year on a different car that I swapped to a 2jz.

Thanks,

-Sean

 

[trd88supra]

my 2j runs the same way when its cold i cant touch the throttle

 

[funky_monkey58]

it not the 2jz supra its a 7mgte in this one. On the supra I put a 2jz in im still fighting with the megasquirt.

 

[hellraiser456]

i believe your ecu needs a rpm signal. it is a very important signal. i would look to make sure your ecu is getting a signal...because if it isn't...that will cause a whole bunch of problems...

this should cause a code however. if you have no codes the engine light with the jumper in) will just blink steadly (once every .26 secs). if it detects a problem it will throw a code 12 or 13.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=26

double check to make sure your ecu has that rpm signal.

The rpm signal will be used for all kinds of things..suuch as ignition timing and fuel injection control.

 

[funky_monkey58]

i believe your ecu needs a rpm signal. it is a very important signal. i would look to make sure your ecu is getting a signal...because if it isn't...that will cause a whole bunch of problems...

this should cause a code however. if you have no codes the engine light with the jumper in) will just blink steadly (once every .26 secs). if it detects a problem it will throw a code 12 or 13.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=26

double check to make sure your ecu has that rpm signal.

The rpm signal will be used for all kinds of things..suuch as ignition timing and fuel injection control.

I was wondering if I had a signal from it since my tach isn't working also. The thing Im stumped on is why it will still rev a bit without the afm hooked up. And run in general without a signal.

Thats the first thing I check in the morning.

Thanks,

-Sean

 

[hellraiser456]

the car will idle without the afm. i wouldn't concren yourself with the afm yet. especially if you have no codes. from looking at the tsrm...the tach gets its signal from a different than the ecu does. the CPS gives the ecu its signal while the igniter is the source for the tach. i couldn't see anything about how to test to see if there is a rpm to the ecu. i would make sure your CPS wires are tight...

if there is a signal...i would start with the basics....and work your way from there. make sure you have spark, fuel and air...and insure that there related parts are working properly. The TSRM will help you with this...also check out the trouble shooting sections as they are helpful.

also please double check you have no codes.

 

[funky_monkey58]

My cps wires are good. My wideband has given me some ineresting insight. At idle with the afm connected it runs lean like 13.5-14.5 and without afm it idles at12.5-13.5 but when it warms up it leans out to 15 and then kills itself at 16 so now im even more baffled.

-Sean

 

[supraguy@aol]

I thought idle should be lean, like 15-18.
I dunno.

 

[funky_monkey58]

Anyone else have any thoughts or suggestions? I just want to drive the car at this point as I am ride less without it and car pooling/borrowing cars is no fun.

-Sean

 

[funky_monkey58]

another update my afm checks out with its resistances over the temperature range. And I just made a new harness for my coils which might help a bit I will keep this updated.

 

[funky_monkey58]

Alright I'm at a loss now. My car stopped starting all together So I replaced my plugs and it fired right up again.

But now I have the same issues when it revs up it hestitates and sputters and will back fire throwing flames out my exhaust. Which is cool and all but I would rather have a good running car. When I unplug my afm it seems like it doesn't have any effect on it what so ever.

I am running individual coil on plugs now. And my idle seems alot more stable with them. As well I have added a full engine grounding kit. As my battery has been relocated to where the back seats would normally be.

Any input is appreciated.

 

[funky_monkey58]

Anyone?

 

[IwantMKIII]

i would suspect the cps

 

[funky_monkey58]

i would suspect the cps

It completely checks out under the tsrm. The air gaps and resistances...

 

[cuel]

Timing issue. Check the marks on the timing belt.

There's a thread in general discussions(I think), where JJ talks about how the ecu has a basic set of parameters to use when it doesn't see a sensor. Kinda like a limp mode. You've unplugged and run the car enough times without the afm, that this may be what's happening to you. Try resetting the ecu.

 

[funky_monkey58]

Timing issue. Check the marks on the timing belt.

There's a thread in general discussions(I think), where JJ talks about how the ecu has a basic set of parameters to use when it doesn't see a sensor. Kinda like a limp mode. You've unplugged and run the car enough times without the afm, that this may be what's happening to you. Try resetting the ecu.

I will check my timing again tonight. I suspect its on but at this point its more of any annoyance than anything.

 

[funky_monkey58]

Alright this thing has added another twist. It has been fouling out the plugs whenever I try to run it. So now I'm thinking it definitely has something to do with the cps. Does anyone know how I should go about this issue? I was thinking rewire it back to the ecu.

Sorry I have been trying to go about this as systematically as possible.

Thanks,

-Sean

 

[KMinAF]

Fouled plugs usually indicate a rich mixture. Back firing and flames from the tail pipe are also indicative of an incorrect fuel ratio.
I would suggest starting with those items that affect fuel mixture. Verify that the ECU is recieving the correct information that it needs i.e. temp sensors, AFM signals, throttle postion sensor, cold start system etc.


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