Wondering if someone could give me an idea on whats going on with my truck. Having problem with no start/hard to start,both low pressure in- tank pumps will run(whichever one is selected),after key is turned. Sometimes they will shut off but come back on when truck is cranked. If engine does start you have to give it gas pedal to keep it running, exhaust is smokey/ gassy. Check engine light also. After switching tanks back and forth for awhile (dual tanks) engine light will go off,engine will run on its own,no smoke. Have replaced high pressure pump in frame,also fuel filter, fuel pressure regulator, and tried a new pump relay(off a Merc Gran Marquis 87). Put fuel pressure gauge on fuel rail 45 psi, 55 psi with vacumn off of regulator. Tried to read codes and got like a 67,67,1,1,5,111(dont know if this was done correctly, used jumper wire on test plugs and read check engine flashes on dash.This problem started day after towing wifes car home, had a few good jolts at times when she had a heavy foot on the brake in her car(dont know if the jolts are related to my fuel problem). Could the dual function reservoir(6 port selector valve) be a problem? Also the rear tank pump is quite a bit louder than front pump. Any ideas? Thanks for any replies!!

 

Rust got in the tank?

Might want to ahve the tanks checked out, Could be some blockage in the line, The jolt coulda stired the rust to the wrong spot.

Sounds like everything should work to me.
I dont know what the codes are. I'll let somebody elese explain those.

 

Talyn, Thanks for reply. I also thought debris in tanks could have plugged something up, but still I'm maintaining good pressure on fuel rail(45 psi) . What tells low pressure pumps to cut off after key is turned on? Gonna test fuel flow out off selector valve is my next guess, also gonna read codes again. Thanks

 

i had a similar problem mine was with the rear tank also. if i had it switched to the frt no problem, switched to the rear it ran really ruff unless i held the gas pedal down and then it would die out after a while. I had a really rusty tank with leaks and when i relaced it this is what happened. so i put in a bottle of fuel injectoe cleaner started truck and slowly started to rev up the engine sat there for about 10 min and every min or so i would push hard on the gas pedal and finallt i reved it up and it has been running great ever since. so i agree it sounds like you have a clog in the line. try some fuel intector cleaner and just keep your foot on the pedal and it should help desolve what ever is there if thats the problem.. Hope this helps