Engine/Transmission (1998.5 - 2002) The VP44/LP Saga is like a bad soap opera

[Fishin Guide]

Try a new overflow valve. The new vp44 does not come with new one like older inline and distributer pumps. This got my psi to 15psi at no load and 11psi wot.

I also fought a bad overflow valve for a long time. My fuel pressure would dump from 12 psi cruising to 5 psi in an instant. The only way to restore pressure was to mat the go pedal and release. Pressure would come back for a while.



I suspected the pump at first and got to try a good known pump for testing. Same issue. Swapped in a 12v overflow I had handy and the problem dissapeared.



Dave

 

[mhenon]

Well... . I put the campaign pump in the stock location along with the in-tank pump today. I am getting 25psi at idle and 18psi at WOT. I am going to keep this setup for a while and see what happens. Based on my research, I don't "think" I will have a problem with too much pressure. Time will tell..... Let's see how long this setup lasts.

MMoyle, I'm about to do the same thing. I was surprised to see the pressure up that high. Guess the little Carter pump can put out decent pressure if it doesn't have to suck fuel through 6' of 3/8 line.

Mike

 

[Fishin Guide]

Sure that's a camshaft he's gripping tightly? :-laf

Don't hate! :-laf



Dave

 

[Fishin Guide]

BlackburnR, tell me more about the overflow valve. Where is it? Easily accessible? Does it really limit max psi in VP? If so, then no one running high pressures should ever have diaphragm problems. I was thinking of a gasser V-8-style Fuel Pressure regulator. Just a thought.



Tim

The overflow valve is on the side of the VP44. It lloks like a banjo bolt and has a return line attached that goes to the back of the block. It's easily removed with a 19MM wrench.



The overflow does not lower pressure at the front of the VP. I have had mine open to atmosphere and I can still maintain 20 psi. The way I think of it is a means to hold some fuel in the body of the VP at all times. It is not a pressure regulator like in a gasser. The fuel still enters the front of the pump and that's where the wear would be.



An inline regulator betweent he fuel filter and the VP is an easy to build piece. Then you could run you fuel supply to whatevre pressure you wanted and dump the rest back tot he tank. If I had an electric pump, I would have that in stalled. It helps take some of the wear off the lift pump and does not cause overheating or cavitation of the fuel as it has a flow path back to the tank.



Dave

 

[GiesJ]

Personally, I don't like the idea of replacing one electrical pump with another. Look at the economics of it and I think a cam looks pretty dang good. Basically, 1500 bones installed. What does a FASS run? Plus install? Plus other items (turbo upgrade etc) to match the performance gains?



The great thing about the helix cam is all of the added performance benifits and the fact that if you go F1 you can run the 12 VALVE lift pump - mechanical.



Do I think the cam will save all VP-44 probs? - No. But I think a truck with the F1 cam will be better protected than one without. Unfortuntaley, IMO, that may not be enough to protect the fragile '44.



There are a couple good threads here and on DTR (I mention that cause Don~ posts there and that guy knows his stuff!) Hope this helped some.

j

 

[NoSeeUm]

Well... . I put the campaign pump in the stock location along with the in-tank pump today. I am getting 25psi at idle and 18psi at WOT. I am going to keep this setup for a while and see what happens. Based on my research, I don't "think" I will have a problem with too much pressure. Time will tell..... Let's see how long this setup lasts.

Just keep an eye own your fuel pressure, if one pump fails it could totally block the fuel off completely.



Jim