Rotary Noob

First, it has been a long freaking time since I have posted.

Second, I have a pretty good idea that this HASNT been posted before.

I had an 88 NA, and have since bought an 87 Turbo chassis.

I have the T2 trans, and the diff, but an NA motor. I am using the NA computer.

Everything was working fine before I swapped the trans+motor with computer into the turbo chassis. Now, the fuel pump, and the injectors do not run how they should (I can jump the fuel pump to battery power, and creates way more than enough pressure)

I kept all of the wiring for the computer connected, and still have the original sensors attached. They are all bolted to their respective places.

The coils fire, and the engine will run if I spray/introduce fuel through the throttle body, or fire the injectors with my tester. The engine cranks with the key, and the dash lights come on as they should.

This is my current project car, and most everything is done, except for the driving part. Any input is appreciated. This has had me stumped for a while now.

misterstyx69

iTrader: (142)

you problem may lie in the TII harness that you are using to the engine.
If you put a N/a harness in That may help you.
also the Fuel wiring has a relay that should be bypassed to let it run.The N/a harnessed Car does not have that,
You need the N/A sensor Part #326 for the MAF,and the pressure sensor.The N/a doesn't see boost,so it doesn't need the N318 Pressures sensor,.

Rotary Noob

Okay, I had checked that previously, but was skeptical just jumping that relay. That solves the fuel pump issue.

It runs fine when I just bypass the relay in the key on position.

I am using the NA engine harness to the computer. I do not understand why the fuel injectors will not fire (since they should only be affected by the wiring that was already attached to the computer) They fire just fine when I put my OTC fuel injector tester to them.

I have the correct pressure sensors attached to the PCM, they are the 326 model, same as the ECU.

Thank you for the input thus far.

Rotary Noob

Alright, I've spent most of the afternoon becoming more and more frustrated.

I know I'll be kicking myself when it finally starts.

So, I was checking things, and the injectors all get 12.67v, to the computer like they should.

The computer however does not seem to be grounding the circut to fire them as it should. Is there an inhibitor or cutout somewhere that I am overlooking? The car does not have an alarm installed, and all of the components that were originally on the engine are still installed.

PhantomSky

iTrader: (4)

hm, this thread brings up a question for me...not to try and hijack your thread anything but..

Would issues would you run into using a N/A pressure sensor with a turbo engine?

RotaryRocket88

iTrader: (7)

It's not really possible to measure injector pulse with your average multimeter. Pulses happen in milliseconds, so you'll pretty much just see 12V all the time. The injectors do need a CAS signal to fire, and something to try would be spinning the CAS gear by hand, while listening for injector clicks. You might also test the CAS voltage values at the ECU to be sure they're within spec.

If using an NA ECU: No timing adjustments over atmospheric pressure (under boost), which is a sure fire way to blow the engine.

If using a TII ECU: Same as above, but now ALL of the pressure measurements are wrong due to a completely different voltage scale.

Rotary Noob

Spent some more time just now, looking for the cause of no fuel injector pulse.

I hooked up a set of noid lights to the injector harness. No light, even as I spun a spare CAS I had laying around. The plugs all fired as they should, but no fuel.

The fuel pump was running, with the key in the on position.

I checked the resistance in the upper injectors, 13ohms. I checked for power at the injector wires, 12.6v.

Then I got my fuel injector tester out again, and fired the upper injectors with the tester.

The car stumbled, started, and promptly died.

Still not understanding my no fuel situation.

All my sensors are 326. AFM, MAP, Pressure Sensor, Variable resistor is the factory one, etc etc.

Any more clues guys? IM starting to think I might have popped the computer...but not certain.