it happened again- fuel pump no go

[SunlitComet]

.box delco the in is and cheaper is delphi just renamed mostly. all right why is my tabelet putting words backwards

 

[tlamot01]

or just drop the tank. i did it on my friends tahoe with hand tools and a jack/jackstand in about an hour. why cut a huge hole in the body right where the fuel access is?


and if you don't plan on selling it, fork out the extra cash for the acdelco pumps. as noted, everything else will inevitably crap out on you.

I only asked that because I've already had to drop the tank once to replace the fuel pump about four years / 30K miles ago. I'm starting to think my no-prime problem is either ECU (according to SunlitComet, all modes of fuel pump are controlled by the ECU on my 98 Yukon) or an intermittent grounding problem (researching the "big 3 upgrade" now), or the (unlikely) fuel pump wiring harness.

All my other older cars had the fuel pump readily accessible by removing the rear seat cushion. I'm just used to it being more accessible even though I never had to change out any of those fuel pumps.

 

[SunlitComet]

How about the frame ground for the pump.

 

[tlamot01]

I have my doubts about frame grounds because once I lay on the starter for about 20 seconds, the truck fires up - every time, and stays lit for the entire trip. If there was a ground problem to the fuel pump, wouldn't it stall my engine at any given moment without warning? My issue is strictly related to the initial 3 second prime circuit. All modes of the fuel pump use the same grounds according to the diagram you posted a while back. (PS, still hoping you'll send me the correct one for my 98 Yukon 4x4). So for my problem, its either a PCM issue or a pressure sensor/switch on the control (power) side of the circuit.

 

[SunlitComet]

moving this convo to that odd issues thread will continue it here.