[hotrodv840]

My lift pump went out a month ago, replaced it with a raptor pump. I was driving down the highway and the truck started to cut in and out (similar to when the lift pump failed before). I loosened the fuel fitting at the inlet of the injection pump and it sprayed hard, fully primed. I loosened an injector nut and no fuel was observed during cranking. I checked codes and only have P0234 (overboost), which has been on there forever, so no codes that would hint towards the injection pump being bad, but based on these events is it safe to say my VP44 has failed? Where is the cheapest place to find a VP44 for my '01? I plan on doing a P-pump swap next year but don't have the time to do it now and need to get it back on the road ASAP. Thanks.

 

[rwilson63]

do you have a fuel pressure guage? if not, get one. did you try turning the high presssure line out further? 1,3,&5 are the ones you want. if they dont spray fuel, try taking them back more. if the vp goes out, it seems like it will almost always throw a code. the fuel pressure guage is really the only way to know if you are getting fuel to the vp during driving. if its cutting out, pm me. i'll be on tomorrow... and pretty much everyday.

 

[hotrodv840]

do you have a fuel pressure guage? if not, get one. did you try turning the high presssure line out further? 1,3,&5 are the ones you want. if they dont spray fuel, try taking them back more. if the vp goes out, it seems like it will almost always throw a code. the fuel pressure guage is really the only way to know if you are getting fuel to the vp during driving. if its cutting out, pm me. i'll be on tomorrow... and pretty much everyday.

I do not have a fuel pressure gauge on it, its on my to do list. I only loosened the injector nut for #1, but I know I loosened it enough to let fuel spray out (I did the same to purge air when I replaced the lift pump a month ago). My fuel filter canister was full of fuel and fuel shot out HARD when I loosened the inlet line at the VP44, so low pressure is good. I can say that the way it died was very similar to the way it died on the highway when my lift pump crapped out. I could notice a very subtle change in RPM pitch at idle days before it died and feared something was going on. At this point I'm going to assume my VP died without throwing a code.

 

[hotrodv840]

I replaced the VP44 and it runs now...but seems to run out of fuel when the gauge shows 1/4 tank and didn't do that before I put the raptor lift pump on....maybe my VP44 wasn't even bad even though I had full prime on the inlet to the VP44 and I cracked open one injector line and didn't see fuel come out, but maybe I didn't let it turn over long enough :-( oh well....

 

[rwilson63]

sounds like the all too familiar 1/4 tank problem. i've seen a couple threads on it and how to get rid of it. if you do a search for it you should find what you need. i just assumed that you had a more than 1/4 tank. my bad.