This is a long story. I am a tech for GM and one of my friends here is working on a 99 3/4 ton dodge diesel, auto. It started up that it wouldn't start unless you primed it. We have replaced to transfer pump filter and other verious things. This still did not fix the problem. So our parts guy got a hold of one of his friends that works for a place that sells reman pumps.
Thatey had a guy come in and buy a pump, but it did not fix that guys problem and that would reexchabge the pump back because he already installed it to his truck. So he gave us his old fuel pump for core price. The pump is supposed to be good. We put the pump on and the truck won't start.
so we changed the fuel module sensor that is internal to the pump and put the old pump back on that did work only you had to kind of give it a jump start with some brake cleaner. The main thing is that this truck did run with this pump before hand. Now the truck will not run. If you spray some brake clean in the air filter like we sis before to get it started in will run until it is burnt off, but the truck will not stay running. we have bled it over and over. We are getting fuel to the pump and out of the return line, but no where else. Out of the six injection lines and little fuel comes out of tow of them, but no fuel out of the rest of them. Why would the pump work before hand after getting it started but not now? Any help on this mess would be great. Thanks.

scooter0803

 

If you are getting good fuel pressure and flow between the filter housing and the injector pump (VP44), then it almost has to to the injector pump. These things are notorious for working one minute...and not the next.

 

Lets see what I remember from what I read. The ( this isthe wrong word but the pressuer relief valve) set @ 15 lb is probably bleeding off at much lower. As for bleeding are you opening injectors lines at the nut at the top of the valve cover? 1,3,4 to bleed the air from the system open them up alot then close them down mostly when they pump fuel out of them . Then bleed them one at a time. When one or two are bled it should start. Mine does. DON'T DON'T DON'T use brake cleaner to start the engine nonononono. If you have to ( out in the bush) disable the manifold heater! This should get it to start and run.

 

Make sure its not sucking air. If either the supply or return lines have a pin hole you will have this kind of problem. Line failure is very common.