I bought a 1999 Dodge 3500 diesel 5spd 24 valve, I was told that if my lift pump is not suppling enough fuel pressure than it would screw up my injector pump! Is this true? If so how do I test my fuel pressure and how would I know my injector pump or lift pump is going out?

 

YES. That's very true. The lift pumps on these trucks were mounted in the wrong location. Electric fuel pumps work better as pushers, not pullers. And being mounted on the side of the block only makes it worst, with the heat and vibrations.
There is a schrader valve where the fuel line goes into the VP-44 injection pump. A test gauge can hook up there and tell you what your current pressure is. You can buy a cheap one or borrow one from Autozone. Well, at least the Autozones around here lend out tools. Or even better, purchase a fuel fuel gauge from someplace like Geno's or Diesel Manor or where every. That way you can monitor your fuel prssure at all times. This is actually the first "upgrade" or "modification" you do, IMO.

 

It is true!

Install a gage, permanent or temporary, to check the fuel pressure. It should read about 12 psi at idle and 7 at wide open throttle. On your '99, you can connect it to the outlet side on top of the fuel filter.


Welcome to DTR.

 

Tanks Guys, I had another question, what would I look for if I thought the injection pump was going out? If the lift pump or injection pump were to go out were could I get replacement lift pump or injection pump?

 

Do you have any codes? I'm not really sure how to test a VP-44. As for the LP, test as discribed above. If everything looks good, start by getting a re-location kit from Vulcan or someone else. Maybe find a replacement spare from EBay or Napa or one of my favorites, www.hoelsidiesel.com