Is the fuel pump also called the lift pump? or are there two different parts?? Cannot find a service manual for 99' and this is my first Diesel Cummins....I changed the fuel filter and tried to prime the fuel line, but it seems it wont fill the filter housing fast enough after about a dozen key on / start positions. I opened the drain port, and no fuel runs out.... bad lift pump? or bad fuel pump?? what am I missing?any help is appreciated.HR 20.

Your lift pump in the stock location is right behind the fuel filter housing. If it works at all you can hear it run or have someone turn the key to the run position and put you finger on the housing and feel it run. If you got nothing at all you have "lost your prime" to the VP44 injection pump which will run without a functioning lift pump, but not well. It cannot pull enough fuel from the tank to run without the lift pump and the pressure head delivered by the lift pump keeps the VP44 cool. You will absolutely need at minimum an OEM lift pump to get your Cummins started. A better solution is a relocation kit to put a DDRP lift pump on the frame rail in front of the fuel tank. An OEM lift pump will cost about $200.00 , the relo kit costs about $100.0 and the DDRP can be had for about $300.00 from Geno's. Now if you only do the OEM pump you will sooner than later probably have to replace the VP44 because the pump may have been wounded by the loss of the lift pump. That rebuilt unit is in the neighborhood of $1,200.00 from many on line vendors. I did all that to my 2002 which had the same fuel system. Diesels are great, but you really need to use them hard to justify the maintenance cost. Good luck.

You need to turn the key on, then just turn the switch to crank position for a split second. just enough to hear the starter bump into the flywheel and crank, release the key to the on position. the fuel pump should run for 20 seconds and time out.

If your going to mod it, I'd get a fass or airdog and be done with it.

Like mentioned, you need to turn the key to start for a split second for the pump to kick on.

Thank you all so much for the information.this truck has 80k original miles. I went ahead replaced the stock lift pump with a new made in USA precision replacement pump from Orielys Auto Parts for $152.00 .Other than the scrapes on my forearms....I completed the fuel filter change and replaced the lift pump in an afternoon. Again thanks for responding.This is my first diesel and just trying to learn all cautions and maintenance to avoid the VP 44 replacement issue. I did fill the fuel filter housing to aid in initial start after bumping the starter. It fired in 3 attempts and is back running
now. HR 20

Notice your location is pothole city. You live in Warren Arkansas? LOL

My digital fuel pressure gauge showed inconsistent pressure with the OEM pump, so I replaced that with a FASS DDRP pump that I got from Geno's. From then on readings were in the mid 20s. In my case I was very happy with near stock level of performance once everything worked properly.

I thought mid 20s was too high for a vp44. Mine reads 14.5 and has been there since I had a guage. It runs perfect and has no problem with sending out black smoke from the exhaust