Ok guys
Just bought a 87 IROC from friend, sat for 3 months, now when you turn on the ignition you cant hear the pump engergize. Wont start, Checked all the fuses both under the dash and under hood, everything is good. Replace fuel pump relay so isnt that. We are getting 12 volts from the the battery to the relay, and then we are getting 12 volts to and from the computer, we also replaced the ignition switch to make sure that wasnt the cause for the pump not getting enough voltage. We get back by pump and we start losing volts, so i dont know if it is one of the connectors that got corroded or what. Checked the grounds to make sure that isnt the problem, but maybe i overlooked a connection somewhere any advice on what our next step should be. Any grounds that if corroded would cause these symptoms??? Should we run a wire from a 12 volt source to the pump to see if it turns on??? Also there is a purple gray and black wire behind the back seat, which one is for the pump??? My buddy had the pumped replaced like 5 years ago, but it wouldnt surprise me if the pump went South. Please help i want to diagnose everything before i have to take the pump out, and replace.

 

Jump the pump, and see if it runs.

 

The Computer only turns the fuel pump on for 3 seconds to prime the system and then shuts it back down when you first turn the key on. If that voltage is present for 3 seconds and your sure there is no fuel pressure then it probley needs a pump