1988 N/A shell with 2JZ NA-T and 7m Electronics

dunnbeetle

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#1
Hi, I've been working on this car off and on for the past few years with no luck.

Mods:
-1988 na supra shell with 2JZ NA-T
-7MGTE electronics
-Map-Ecu 1
-IS300 Coils wired to 7M igniter
-Innovate LC-1 wideband controller
-Walbro 450lph fuel pump
-Had 1000cc injectors(e-85) but now has 550cc(pump gas)
-AFM delete(2.2k ohm resister in pins 1 and 2 of afm connector w/mapecu)

A few years back I had the car idling(roughly) on the above setup with the 1000cc and e-85. At the time I lived 4 hours away from where the car was stored and was crunched on time. When we had it running we noticed a oil leak so we put it in the garage and I wasn't able to touch it for a while. Next time I was able to work on the car(few months later), it would not start. As I said, this was a few years ago...I became busy with work and life so I haven't had much time to figure it out.

Here is when it was running: https://photos.app.goo.gl/y7jTAf5R7LoFI6bC3

Since then, I changed the injectors to RC 550's and put pump gas in to try to get it going. I have worked on it here and there and this has been what I have figured out so far:
-Fuel is getting to the injectors at least.
-Compression is good
-At least 2 of the plugs are getting spark(only checked 2)
-Car will fire when starting fluid is being sprayed in the intake

Today I disconnected the map-ecu and hooked the oem o2 wire back up and attempted to start the car with the afm and stock ecu and had no luck. I was able to get the car to fire a bit when my brother was messing with the cps while I was cranking. I double checked physical timing and that looks good. Also, I reset the position of the cps while the engine was at TDC, multiple times. Not sure if there is a gremlin in the wiring somewhere or if the cps is bad. I hard-wired the CPS after all this thinking maybe the plug was causing the issue, but still no luck.

I have checked the grounds by the intake and they are fine. I am also getting code 32 right away when I turn the key, even after a reset. It's possible the afm is bad, but it was fine when I used it last(a few years ago).

I don't have a ton of time to work on this, but any suggestions would be appreciated. Thanks.
 

dunnbeetle

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#3
So another year passed...decided to take another crack at it today.

I removed the cps, and took a 2jzge distributor and removed the rotor(basically making it a cps) installed that in its place. Bought a connector and pigtail so I could connect it. Wired it up, installed it with the engine at TDC(yes I checked with the #1 spark plug and a rod), so when it was inserted, the distributors rotor would be pointing at the #1 pickup on the distributor cap.

Attempted to start it....nothing.

Ok, so I went to check compression and spark again. Cold compression was between 125 and 140psi on all cylinders....not great numbers but it was cold(30 degrees where I work on it) and I only did one cylinder at a time. I really doubt compression is preventing the engine from stating. I also had spark from each of the coil packs/plug wires.

Ok, so physical timing should be dead on, I have compression, and I have spark....so maybe fuel?

Last year I checked the #1 injector and it was working fine. I smell gasoline after cranking a bit too.

ANYONE? I'm clueless at this point.
 

3p141592654

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#4
My 2cents. The problem is not the CPS. If you get a spark the CPS is working. You should put the CPS back in like you had it before.

You need to focus on the AFM. Code 32 says your AFM is not wired up properly or is broken.

Since the map-ecu rewires KS signal, maybe you dd not hook it back up properly. You need to make sure KS is connected to the AFM like this. I think it is very likely KS is not connected to the ECU properly.

ks.jpg map.jpg



KS is the blue wire in your diagram.
 

dunnbeetle

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#5
So I was talking to my brother about this last night and he was like, "well those cars don't have a map sensor stock, so where does it get Its barometric pressure reading from?"

I was jus like...uhhhh no idea. Then I remembered that code 32 on pre 89 models is for afm/ hac. Hac is where the ecu gets the barometric pressure from. Since this is a NA shell, there was no sensor in it.

I've read that the car should run with no hac sensor, but I've also read that it can affect timing. So maybe it's throwing it off just enough?

I'm guessing I had the mapecu wired up correctly before and that's why it worked...because it shouldn't need the hac with the map. But as I've said, I rewired it so the car is only using the oem ecu, and I have tried 2 different ecus.

I do happen to have another pre 89 turbo supra sitting here so I'm gunna grab the hac out of that and give it another go. If that doesn't work, I may just check the wiring for the 5th time and possibly hook up the mapecu again.

Thank you very much for the suggestion. While I have a little knowledge on this stuff, when I get stuck on things like this my mind gets blocked and I can't even think about possible solutions.
 

dunnbeetle

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#6
Ok, hooked up the hac....and no difference.

I no longer get any CELs, so the wiring should all be good there. I did a quick check on some of that and everything looks normal.

I decided to spray some starting fluid in the throttle body. I got a couple big bangs but that was about it.

At this point I'm thinking more along the lines of it being fuel related. I bought the rc550s used from someone on here and I assume they are fine, but I'm to the point where I'm going to have to pull the rail and test each one.

If anyone else has any ideas let me know. It's not critical it gets done as this is a project car, but I'd like to progress some day lol.
 

3p141592654

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#7
Your need compression, spark and fuel. You have the first 2, but no fuel.

The primary sensors for the car are the CPS and the AFM. CPS times the engine, and the AFM maps the fuel. My bet is the AFM is bad. Its highly unlikely all 6 injectors are bad. Fuel pressure should be check though.
 

dunnbeetle

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#8
I guess I could throw a different afm in quick before I start tearing out injectors. I know the rail is getting pressure because I've disconnected the line to that and there's fuel to that point.

Only thing that might be a issue is something causing the injectors not to fire. Last year I checked the 1st one and it was firing fine...so I assumed they all were.

But yeah thanks. I will try out a different afm 1st tomorrow when I work on it again.
 

f00g00

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#9
Injectors could be clogged. You could take power and try each one with the plug off and see if it clicks. Just take two spare injector pins and a power source and touch the pins.
 

dunnbeetle

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#10
The car did sit with e85 for a few months. But after we couldn't get it running we drained the fuel tank and purged the line before we installed the 550cc's and added pump gas.

Thanks for the suggestion. I might still end up pulling them out but at least I can try it first.
 

f00g00

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#11
If the injectors are low impedance you will need a resistor pack wired in.
 

dunnbeetle

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#12
I believe I did have one hooked in but I will double check. Didn't get around to working on it yesterday.

Originally I had this swap in a 91 turbo shell but the wiring was all hacked up from the previous owner and I found the NA in good condition for cheap. I'm pretty sure I took the resistor out of that.

I was told the injectors were low impedance from the member I purchased them from on here. Still have the conversation saved.
 

dunnbeetle

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#13
Worked on it a bit today again. Was looking at the firing order and noticed I had something messed up. I'm running is300 coil packs basically wired up like the 7mgte ones would be. I had 1&6 together, 2&3 together, and 4&5 together. Changed it so it was 1&6, 2,&5, and 3&4. I thought for sure this would be what was wrong...but no, still nothing.

Really didn't make sense either as the plug wire that was connected to the coilpack on #5 would not reach #2. Either would any of the other ones(except the one from #1 to #6). I went to my brother's and picked up a plug wire that would reach. I had this running at one point and I'm not sure how if it was wired up the way I had it. I threw in some starting fluid after this and it acted like it was trying to start but still wouldnt.

Anyway, started looking into fuel. Took off the fuel line to the rail, hooked it up to a few injectors, plugged in the #1 injector pigtail, cranked it over....none pushed out fuel. Did this last year and I know it worked. Doing this by myself isn't the easiest so I'll have to wait until I have someone to help out one of these days.

I am getting fuel to the rail, but not sure if the injectors are firing. Not sure what would be preventing them.
 

dunnbeetle

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#14
Forgot to mention that the injector resistor is installed. Also just picked up a noid light kit to see if I'm even getting signal to the injectors.
 

dunnbeetle

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#15
I haven't had a chance to test anymore but I was looking online a bit and saw that if the afm hose is not connected to the turbo, it could cause issues.

Originally I had it running with no afm and a 2200ohm resistor in the connector pins. But after troubleshooting so much I just plugged in the afm to make sure I had that signal.

I've also read that the afm shouldn't need to be plugged in for the car to start.

So if it doesn't need to be plugged in to start, why would it matter if it's connected to the turbo?
 

dunnbeetle

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#16
So hooked up the noid light and the injectors are not getting pulse.

Checked the grounds that go to the ecu with a test light and they were fine.
The only ground that did not test good was "E2 - Sensor Ground". Looking at a diagram, this does not actually ground except it must through the ecu or something.

I'm not really sure where to look at this point....I've never had to deal with it. If anyone could point me in the right direction it'd be great. Thanks.
 

3p141592654

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#17
1) When you crank do you see the tachometer move?

2) Do you have 12 V with ignition on at injector connectors (solid wire colors red, yellow, black?)

Image31.jpg
 

dunnbeetle

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#18
1) the tach does not move, but in mapecu i see rpm signal...

2)I just tested the #1 injector connector and i couldn't tell what wire was the yellow because it had aftermarket connectors that have been soldiered and heat shrunk, so i tested both pins. both showed 12.1v...
 

3p141592654

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#19
So 1 is fail and 2 is pass.

Looks like the ECU is not firing the igniter which is usally due to a problem with the CPS signals (NE and G1 G2). So focus your energy there.
 

dunnbeetle

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#20
So i did wire up the 2jzge rotorless dizzy up the other day and I was pretty sure the wiring was correct. I will have to take another look at that. I assume that dizzy will work as the 2jzge guys always use a 7m cps to delete their distributors...
 

3p141592654

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#22
correct. I assume thing have gone south since you did that test. And you seem to have power to your injectors so they should be firing if you have ignition. The two go hand in hand
 

dunnbeetle

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#23
Well i just ran out and pulled #2 and that is 100% getting spark....maybe if g1 and g2 are mixed up on the cps wiring it will still spark but not send the correct signal? i dont know.
 

dunnbeetle

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#24
Ok so I just realized that since the shell is a NA, and it basically has a 7mgte swap, the tach will not read due to different resistances or something.

That being said, when I hook it back up to the map-ecu, it reads the rpm signal just fine.

-Just re-went through the ground connections again, they are all good. One was pretty corroded, figured it might be it....but it wasn't.
-Pulled a AFM from another turbo supra sitting in my yard to try, still no injector pulse.
-Pulled another ignitor from the other car as well, same issue.
-Swapped both ecus back and forth while trying all this, same issue.

Thinking about tearing the engine harness out now and starting from scratch...
 

Piratetip

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#25
You just need to locate the root cause as to why the ECU is not grounding the injectors.
That sounds like your issue to me.

Start the troubleshooting tree:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?S=FI&P=10

Pins #10, 20, 30 of the ECU should go to ground if it is actually trying to fire the injectors.
Check with a high speed DVOM at the least or a scope.
Check at the ECU pins directly while cranking. (backprobe)
Then check at each Injector while cranking. (backprobe)

You do have the fuel pump running correct?
There is fuel pressure at the rail?
 
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