[91 diesel]

Another possibility (because I had this happen to me 2 years ago....) is that your lift pump went out. I changed my fuel filter, filled it up and went to crank the truck and it wouldn't start. There were no leaks, vacuum or otherwise. My fuel pressure gauge showed 25-30psi before changing the filter with no issues driving. After running through everything, a friend of a friend that runs a garage mentioned that he had a 12v cummins lift pump 'go out' during a filter change one time before. I had 287k on the truck then and thought 'what the hell, why not'. Well, wouldn't you know, a new lift pump put on and the the truck fired right up (basically...). So if you think you're doing everything correctly, no leaks, and you're over 250k on your lift pump, you might want to change it out. My only explanation for it is that when the system lost it's prime, the failing check valves in the lift pump came to life. Looking at the original lift pump, that seemed to be the only problem - two of the check valves weren't very checky! Priming using the plunger was unaffected and I could prime until the cows came home and it still wouldn't start/run until I changed the lift pump.

 

[91 diesel]

x2 on sticking with the factory style lift pump. You only have to change them out every 250-280k miles. I haven't heard of anyone getting that kind of maintenance free life out of an electric lift pump.

 

[91 diesel]

GAmes, any idea what would cause that woodruff key to shear? I assume it's not very common but sounds like a good thing to keep around 'in case'.

 

[91 diesel]

You can just wash out the prescreen filter. They aren't meant to be replaced unless torn. I don't know where you're located, but even in Fairbanks AK (or maybe because of Fairbanks!) I was able to get a Cummins lift pump from a local truck shop (big truck/trailer type shop). I personally wouldn't waste time on a potentially iffy lift pump, buy (and install) once, cry once. Especially if this is your transportation.

 

[91 diesel]

So was it a lift pump? or the heater/strainer not being tight do you think? I thought in my case it was extremely odd (especially because I have a FP gauge and it was 25-30 psi right before filter change) that the bad lift pump suddenly showed because of a filter change, but I did want people to know that was absolutely the case with my truck.