I HAVE A 89 GTA 350 TPI I AM NO GETTING NO INJ PULSE THE COLD START INJ WORKS BUT NOT THE REST ENGINE AND HARNESS IS OUT OF 87 IROC ANY IDEAS

 

Check the 2 "ECM" fuses.

 

I HAVE POWER TO ALL FUSES THERE IS 12 VOLTS TO THE INJECTORS WITH THE KEY ON BUT WILL NOT PULSE

 

I read you similar post on the TPI board. Unfortunately, I misunderstood the symptoms. I was under the impression that the service injectors were firing but not the cold start. It seems I may have had that backward.

Am I now correct in assuming that you are getting no pulses to the service injectors?

I also understand that you have 12VDC at both injector harnesses, so that would eliminate the INJ1 and INJ2 fuses as possibilities. Since the ECM provide a ground path for each bank/harness, a reliable ground at the engine is crucial. There are a few ground wires attached to the rear of the right head. Make sure those grounds are clean and tight.

If so, the ECM will ground each bank of the injector sets once every revolution, or every four distributor reference pulses. The ECM needs to have a reliable distributor reference signal from the HEI switching module, so you might want to check the connectors at the distributor. If the circuit is good, make sure the ECM has a reliable case ground.

Incidentally, are you testing with an injector tester or scope?

 

I answered in the other forum where you posted this...sounds like you're running a VATS chip and your '87 doesn't have VATS hardware.

 

using 87 chip and harness

 

Time for a ground check. The ECM pulses the injectors by switching ground, so whip out your wiring diagram and start probing.

I'd begin with the grounds at the rear of each cylinder head, and verify the ground strap from the rear of the pass side head to the firewall.

 

A bad ignition module can cause your injectors not to pulse. Bench checking the module IS NOT a reliable method to determine if it's good or not.

Been there, done that on a 92 Z28.

 

I was going to suggest the ignition module too, but I think the computer needs to recieve some reference pulses to fire the cold start injector. A bad pickup coil could make similar problems, but again I'm unsure if the cold start injector would fire.

 

I think it's the ignition module too. I had the same problem and I replaced my ignition module and it fired right up.

 

First thing I would do from here is check for spark and if you're getting spark...it's not the ignition module..and if you don't get spark..change your ignition module and don't even bother having it tested. Like stated before, it's a very unreliable test.

 

Your ignition module can still be bad even if you have spark.

I speak from experience.

 

Perhaps the ECM is bad?