How can you tell if your lift pump is going bad or has gone bad? Is there any change in performance,sounds,etc...

 

When most lift pumps go bad you do not even know it. Most failures are seal related with fuel leaking out the primer plunger or down the pushrod and into the oil pan. Some people notice a pool of froth under the blow by tube from an internal leak, or see fuel on their finger when pushing the primer, or their fuel mileage starts dropping dramatically.

Other lift pump failures are most often noticed when they stop pumping, and that is usually a fairly quick failure. When that happens the fuel will either be foamy, or no pressure or very low volume. Most often the rig will quit running or be very hard to start and then die frequently in hot weather.

Slow loss of power is generally plugged filters, air leak in the turbo plumbing, or an air leak in one of the fuel filter housings or the flex lines, or the injection pump overflow valve giving up the ghost.

Slow loss of power and a gradual tendency for the truck to start to run high EGT's is generally the timing sliding down below 9 degrees.

 

Thanks RCW thats all the info i need. Sounds like I have a timeing and not a lift pump problem, but now i know what to look for. Thanks alot