Archived Erratic fuel pressure

[hcpBILL]

My fuel pressure from the lift pump is getting erratic. Has been as low as 3 pounds but is jumping around. No loss of power, boost and EGT is normal, even at 3#.

I am on a trip and have another couple of hundred miles to go today. Pressure is a bit better with a full tank of fuel, 4-8 pounds. Can anyone guess how long this LP will last? This lift pump has about 10,000 miles on it, the truck has 49K. When the last one failed I did not have a pressure gage on it so I have no idea how long they go once the pressure starts to go up & down. When I installed this one I was told it was the most up-to date unit, cummins part number ending in "105". Is there a better one?

Thanks for the help

Bill

 

[Casey Ray]

Bill,



If electrical gauge, check the sending unit and make sure everything is tight. If possible check the pressure with a mechanical gauge at the schrader valve. If you have a mechanical gauge on, they are pretty reliable, I'd swap out the lift (transfer) pump asap. I had the 2nd lift pump last 2k on my truck, 1st one gave up the ghost at 11k, swapped out the third at 36k for the FASS II.



Casey

 

[hcpBILL]

Thanks Casey.

I have a mechanical gage I will be installing today. When I replace this one it will go down by the tank. I have not heard of any failures with a new pump installed down there.

Bill