1990 IROC 5.0, 5 speed. Fuel pump died, car sat 2yrs, replaced fuel pump and filter. Disconnected both the feed and return lines from the fuel rail while turning over the engine, got fuel both places. Checked ohms on each injector, 15.8-16.2 on all 8. Poured gas into the plenum and it starts and runs til gas is gone. So, have gas, have spark, but injectors seem not to be firing. Anybody have any other ideas. Thanks!!

 

Did you check the injector fuses under the dash?

 

yes, and the ECM Fuse. All 3 are good. Thanks for the reply

 

to be sure the injectors arent firing, do you have a noid light to verify theres no juice when spining the engine?
I would suspect a vats issue. My iroc is an 89 model, was having some issues and changed the ecm out, put the stock memcal in the new ecm and engine would turn over all day but not fire and would only fire off of ether. Thus the injectors werent firing.
The old ecm i took out had a moates board attatched to the prom. at some point the vats had been bypassed and the ignition switch/key changed out to the standard key so I have no vats key at all.
I put the moates board with the stock prom or memcal whatever you prefer to call it, into the new ecm, and dam thing fired right off and runs smooth as a kitten.
Im figuring the moates board has been programed to bypass or disable vats. As from all my research Vats will disable starter and fuel injector pulse.
Have you another key to try?

 

yes, I had 2 different keys and tried both, security light comes on when you first turn the keys but goes out right away. and I still checked my ground connections also. I'm starting to lean towards an ignition module or the ECM. Thanks for the reply

 

you would think the ignition module it still wouldnt fire when you pour fuel in the throttle body. could be weak i guess. Advance can test em for you. I got my ecm from the dealer was ac delco cost like $119 exchange