I have a 1990 Camaro RS with a rebuilt 5.7L TBI engine out of a late 80's truck. The issue that I'm having is that the fuel pump does not come on when I have the key on either the on or the run position.

I have already tested the fuel pump prime connector and the fuel pump does come on and brings fuel all the up to the Throttle body so i don't believe the fuel pump is bad.

I have checked every fuse that I know about and I have replaced the fuel pump relay and have put 12V directly to the grey wire fuel pump part of the relay and the fuel pump does come on so everything after that point i would think is OK but before that I'm not sure of.

The Injectors do fire every once in awhile and they seem to fire correctly so I don't think they are the issue, they also have voltage and resistance when the key is in the on position, but my noid light doesn't seem to light up when it's in the run position. The car does start with starter fluid.

I have also recently put a new coolant temp sensor, cap and rotor, new battery, starter and starter solenoid, and I cleaned and put in new gaskets in the TBI.

I've been trying to figure out what the issue is for at least a month now and I believe that its down to the ECM but i could be wrong. So if there is any advice you guys can give me i would greatly appreciate it! Thank you in advance!!

PS, the ECM is a 8746 model and from what I can tell it doesn't appear to be fried or damaged.

 

Does the orange wire at the fuel pump relay have power at all times? If not, check the inline fuse on the fender by the battery. What was the original engine in the car? TBI 5.0 or something else? Did you test the drk green/white wire at the relay to see if it powers up the relay?

 

Good news! I actually just solved the problem today! It was my VATS system so I ended up just bypassing it with a few resistors and it started right up!

Thank you for all the advice tho!