hi yall,
i have read until my eyes are crossing, but haven't found anyone else posting symptoms i am having.
I have determined that I have a fuel delivery issue. It will run great for a while, (32psi at first) but then the fuel pressure starts falling until it finally dies. I checked this with a fuel pressure gauge as I duplicated the symptom. As it was fading out last night I got under it so I could listen to high pressure pump and it was making strange noises as pressure was dropping and the engine died out so I thought "a-ha!" Replace high pressure pump and the fuel filter, started it up, 32psi, and 20-30 minutes later pressure starts falling and she dies out. The high pressure pump still running and sounding better than the old one did until it shuts off because engine isn't running. This was all using front tank tonight. I get the wife to help with key on and off and i can hear the front in tank pump run and the rear tank does not run when switched. I am thinking that the rear pump went out some time ago and the front tank is now going weak and not supplying enough to the high pressure pump but I dont know what the in-tank pump pressure should be. Can it be checked at the fuel rail if I unplug the high pressure pump?
I would sure appreciate any insights

 

yes check it at fuel rail,i no 92s had a recall on fuel pumping from one tank to the other,there is a small screen around suction on in tank fuel pump,might have stuff in your tanks

 

If your truck has a frame pump it can't be a '90 must be an '89 or earlier, but regardless I'd suspect you have a problem with the intank pump or the dual function resovoir.. that thing on the frame near the frame pump with all the hoses going to it.

 

With it running for a bit and then losing pressure.... If I was a betting man... I would say you are sucking up crud from the bottom of the tank and clogging the pick up screen...

Run a hose from a gas can to the pump and see if the symptom persists...that would rule out the clogged pick up...

 

PULLED FRONT TANK. FUEL PUMP IN FRONT TANK LOOKED PRETTY ROUGH PUT NEW PUMP IN FRONT TANK. NEW PUMP IN FRAME RAIL. SHE NOW RUNS LIKE NEW. REAR TANK PUMP DOESN'T WORK AT ALL, BUT THAT WILL BE A PROJECT FOR ANOTHER TIME AS ONE TANK IS SUFFICIENT FOR WHAT IT GETS USED FOR NOW.
SIDE NOTE: WITH MY GAUGE ON THE FUEL RAIL, I COULDN'T GET A PRESSURE READING AT ALL FROM THE TANK PUMP ALONE , NEW OR OLD.