Engine/Transmission (1994 - 1998) lift pump problems

[WDaniels]

Friday I went out to start the truck and it took about 7 or 8 seconds of cranking to get it started and then it ran rough for another few seconds before running smooth. Saterday was worse and almost didn't start. After it started it stayed running. When I shut it down it would start with no problems within say, an half an hour, but after that it would start hard. But today it would start up ran a few seconds and quit. After cranking about 10 to 15 seconds it started but only ran for about 30 seconds and then petered out. Pulled the filter and it is almost empty. So I started looking for air leaks in the lines but cannot find any. The fuel solonoid works as advertised. Can or does a lift pump go out like that. I've almost got 250k on it and it has not been changed that I know of. If anyone has any suggestions they will be greatly appreciated. Thanks,

WD

 

[MAllen1]

Two things I would be suspect of---1) check the pressure of the lift pump. 2) If I remember correctly, there should be 2 rubber hoses coming off the back of the lift pump, down the firewall, to fuel lines below the truck. If memory serves me, most 12v engines ran a mechanical lift pump w/this "rubber hose " setup. Those rubber hoses were prone to cracking and sucking air.

 

[Joe G.]

You may have a bad fuel heater. There are other possibilities. Email me at -- email address removed -- for my 12 valve fuel supply system write up, how it works and how to fix it.

 

[edgeman]

check all the fuel lines for cracks especially behind the manifold. they are prone to cracking and dry rotting. LarryB's makes a line kit to replace the lines. Just my 2 cents.