But my VP44 sucks!!

So my truck is dead. Won’t start. It has been having trouble starting for a while and it finally gave up the ghost.

I had thought from my last thread on this topic that there might be air in the system. In that regards I tried a few things to purge the air.

1) I loosened the left 7/16 bolt on the top of the fuel filter and bump started it. Once fuel started to come out I tightened it back up and sealed that.

2) I loosened the bolts going from the high-pressure fuel lines into the top of the engine and cranked for quite some time to purge the (alleged) air from the high-pressure lines. About 30 seconds total crank time. Well, no fuel came out at the end of the fuel lines.

3) I then checked the amount of fuel going from the fuel filter to the fuel injection pump (which by the way is a hard place to get to). I pulled off the hose from the fuel injector side, put a 64 oz jug on the end of it. Bump started it and almost overflowed the jug, so plenty of fuel getting to the vp44.

Now what? Is the vp44 dead? Is there actually air getting into the system? Any ideas on what to try next or should I just break down and buy the VP44 and replace that?

Any help or ideas would be greatly appreciated.

Keep in mind that the truck won’t start at all, just crank.

 

The VP44 is a possible problem, but still an expensive guess. It would be wise to check codes, I can't remember if you can use key cycles to do this on a 98. On 98's I saw a couple which could have an intermittent connection on the VP44 electrical connector. You can unplug this connector and very gently "cave in" the female terminals slightly with a seal pick. There is a power and a ground wire in this connector too that should be verified. In the service manual, there is a diagnostic "no start" flow chart, with wiring diagrams, that would definitely be an asset here too. You might be able to find something here with a search.

 

The key on key off to read codes only works on diesel model years from 2000 & up.

Try loosening the lines at the head on a couple of the injectors a turn or so and see if you're getting a strong fuel flow there.

CAUTION
The fuel pressure at this point is extremely high and will spray through your skin if you get too close.

If there's an air pocket, this will remove it, if you only get a dribble of fuel, it's most likely Injection Pump time.

 

Shovelhead, refer to item 2. No spray whatsoever. VP44 time?

 

sounds like a new VP is in your future to me.