Looking for my next troubleshooting step regarding my 88 GTA 5.7L.

Bought the car and put a donor TPI in it. The car will not run, and I narrowed it down to no injector pulse/no voltage. Performed a noid test on the injectors and the light just barely turns on.

I have good fuel pressure at the rail - confirmed with a pressure gauge on the Schrader valve. I have heard a bad ECM could cause this. I have a running 88 GTA that I took the ECM out of and tried it, and no difference.

I have working ICM I swapped out as well and nothing changed.

Each injector has resistance just over 16 ohms.

The car has spark, fuel at the rail, just the injectors aren't functioning because they have no voltage.

Where could I test voltages to narrow it down?

Thanks

 

If the noid light comes on there is power at the injector lead.
have you checked for power at the injector connector ?
some 88 late model had vats.

 

There is power but not 12v's with my multimeter on the injector connector I'm only getting 0.5 to 1 volts while cranking.

It does have VATS, but there is no security light on and it does crank fine. If VATS was the issue would it not disable cranking over the car as well?

 

Check c207 pink/blk wire for power and corrosion.

 

Checked the 207. Pink/blk I have 12 volts there, clean terminals no corrosion.

 

Verify the distributor is not 180 degrees off. I just went through the same stuff you are going through now and that was my problem. I ended up removing the driver's side valve cover and rotated the engine until both the intake and exhaust valves were closed. Pulled the distributor cap and the rotor should have been pointing at #1 but was pointing at #6. Re-stabbed the distributor correctly and it fired right up.

 

Confirmed the distrubtor is not 180 degrees off. I just installed a distrubtor on this engine last week. Found TDC on the compression stroke. Put the cap on so the rotor points between #1 and #8.

 

Anyone else have any ideas on what/where I could troubleshoot or narrow down this issue?

Thanks!

 

If you unplug all injectors on one bank and check for power you should have 12v. If you don’t than the issue is the wiring from c207 to the injectors. You can ohm out the wire to see resistance.

 

Check the ground on the back of the head.

 

Check the grounds on the back of the heads. Some have studs if it’s a stud make sure it’s tight in the head even if the nut is tight.

 

I have the car running now. I cleaned up the grounds, still wouldn't fire. Ended up trying another ECM after the grounds were cleaned up and it finally runs! I'd say a bad ground and a bad ECM. I tried this ECM before the grounds were all taken apart and cleaned up and It didn't fire. It's not running on all cylinders, but each injector is getting the required pulse at least with the noid light tester.