Hello, my 1986 Fiero GT AT has a cold failure and the engine stops if it does not accelerate. The fuel-air mixture is not correct. It has all new sensors, new injectors, the computer does not display an error code. We no longer know what to check.
Before I continue spending money, I would like to test if the problem is with the ECU. My mechanic has a Chevrolet Lumina APV 3.1 ECU that works properly. Externally it is the same, but I don't know if the internal connections match. The idea is to know with certainty if it is the same one that the Pontiac has, so we can test it in the car and see if the fault continues or not. Does anyone know if this test can be done? Thank you!

Most likely it will not work, and could possibly damage your friends ECU.

You can test your ECM

I had 'weird problems' with an ECM in a different vehicle, so I sent my computer to ECU Exchange for testing.

They found a bad power supply which created distortion on the reference and system voltages.

The grand total was around $140

I bet that you will find a ECM service like ECU Exchange in Argentina

If not, this is the service I used in USA:

ECU Exchage
https://www.theecuexchange.com/
https://www.theecuexchange.com/contact-us
Or call (561) 408-6375

------------------
Original Owner of a Silver '88 GT
Under 'Production Refurbishment' @ 136k Miles

Sounds more like your IAC is not working...

As Joe said, do not use another GM ECM not designed for your year Fiero. I don't mean to be harsh but why do so many Fiero owners do not bother to invest in a multi-meter, fuel pressure gauge, ignition tester and a scanner. My suggestion to you is measure your fuel pressure . It should be about 40-43 PSI .

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

quote Originally posted by olejoedad: Most likely it will not work, and could possibly damage your friends ECU.

Thanks, I won't do the test.