Engine/Transmission (1998.5 - 2002) VP44? MAP Sensor? - Power Problems

[SConklin]

I recently killed my stock lift pump (it ran for a while at low pressure, even stalled the truck once from lack of pressure). I replaced it with a FASS, and am running that now. However, since installing the FASS (and being able to run the truck harder again since it has fuel pressure again), the truck feels slightly low on power and smokes less at WOT (less fuel going through?), and while running at highway speed, often cuts out the throttle (no matter how hard I press down, there is virtually no throttle response, no matter what I do, then after a random while, it kicks back in), it now feels like it's defueling around 2600rpms in 6th as well under WOT, and it occasionally runs rough, and shakes the truck more than usual, like the cylinders are misfiring for a while right after starting up on some days.

I had a 0216 code, for the pump timing failure, and a map sensor code, both were cleared, and both came right back as soon as the truck started back up. I don't know if these are related in any way. I have been planning on getting a new modified VP44 from Piers now. I have been thinking that the VP44 is the problem, however, I don't know how much the MAP sensor plays into it either. I also want to be 100% sure before I plunk down $2k for a new Piers VP44 (as much as I like the idea of the upgrade). Just for info, I have a drag comp, and dd3's as well, but the problems seem to happen whether the drag comp is on or off, or even plugged in for that matter.

Any ideas exactly what the problem is, or what I should do? Thanks for the help!



Skyler

 

[liftedlpg]

On cool mornings, sometimes had bad throttle response for a short while, then ran ok. A few weeks later temp got to around 0 and truck would barely run(thought I had gelled fuel). Ran about a week and died big time. Could start with starting fluid but ran bad. Since may warrenty is expired anyhow,took to dealer and for 60 bucks tech told me I had a bad map sensor and bad vp44. I bought parts and replaced myself.

 

[bandrew]

I've been having the exact same problem only at first i thought it was my ez, but it was very weak once I unhooked it. So I've been trying to get it fixed. It's just that dodge dealer doesn't want to swap it out at the drop of a hat (new one is like 1200).