Greetings,
I really appreciate your website and making your knowledge and experience available to us shade-tree mechanics.
My problem child is my 1995 Chevy Beauville Van, 5.7 TBI, 4L60E Trans (I think), It's really in great shape and I plan to repair the rusted lower body panel and make her new again. But she's currently giving me fits.
I worked on it one evening, installing some fog lights. I ran my fused switch line to the a pin on the fuse block. Job was done, I shut her off, and went in for the night. She would not start the next morning.
The truck has it's original fuel pump (which I admit still could be the problem if there's not ENOUGH fuel pressure). However, when I jump the FP Relay, and crack the fittings at the base of the TB, II get a very healthy spray. If I pour raw fuel into the TB, she will light. I don't have a fuel pressure gage to check, but I believe the pump to be OK.
I have replaced all the fuses and Circuit Breakers. On two occasions the van DID start, but ran very rough. I attribute this to the FP Relay fluttering as I had a test light connected to ground and the relay activation lead. It flashed wildly and pulsed to the engine ignition. Eventually the engine would die, not to start again. This is what leads me to believe that this is an electrical issue.
She turns over freely. No known mechanical issues. I have + power to the injectors but they are not activating that I can tell through my stethoscope (long screwdriver to my ear).
I have swapped the PCM with a known good unit. I have also replaced the FP Relay. If I jump the relay, the pump runs at the same pitch as it always has. Sound just like the one in my 1995 Caprice. Are there any fuseable links or hidden fuses I should be looking for? Everything seems tobe in order under the dash. This has not been all cobbled up like so many old vehicles. It's all original and in very good shape.
So, assuming there is adequate fuel pressure from the pump, the PCM is good, all the fuses are good, the FP Relay is good, there is good gas in the tank, the battery is strong and connections are clean, what am I missing?
I am hopeful you can help me. My job is depending on this van.
Sincere thanks,
Chris Baker
Studebaker14@comcast. Net
Friday, July 24th, 2020 AT 12:20 PM
(Merged)