Installed lt1 rebuilt engine in a 95 z28. everything hooked up, fuel pump primes off the test conector. when i turn the key, all the lights work, but no fuel pump. need help fast

 

Look at the schematic for the relay.

-Pink should have +12v with key on.

-Dark green/white should have +12v when the computer commands the pump on (for 2 seconds when the key is first turned on and continuously after the engine is running)

-Black/White = continuous ground

-Gray = +12v to pump when relay is activated

 

what is the actual sequence that the computer does or looks for from the time you turn the key to the on position until the engine is running.
the computer looks for what
the computer does what then?
the computer needs to see what to do what?

 

Turn the key on-computer operates the f/p for 2 seconds. I don't think it looks for anything, though a security issue might intervene (unproven).

Crank engine- computer looks for opti pulses. If present the f/p will run. If not, the f/p will not run.

Engine running- f/p runs.

 

I had an issue with my pcm ign fuse that gave the same results. Fuse was not blown but it wasn't getting a good connection or something. I also could not connect to the pcm to scan it. I cleaned all the corrosion I could from fuse and fuse holder and put a little dielectric grease on the fuse and its been fine since. The test shoebox reccomended should show any problems.


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