Ok, after I (we, BigBlue) installed my gauges this past Sunday, I noticed that my fp was too low.

1st post... https://www.dieseltruckresource.com/...threadid=42150

I took the truck in to the dealer this morning and told them the info.

I talked to the dealer this afternoon and he said my lift pump was bad, just like I suspected.

My Q is this..even after the new lift pump is installed, and FP where is should be (16 psi for me at idle, instead of my curent 9 psi) is there a chance that my vp44 is shot? If my fp is at 16 with the new lift pump, can I still have a bad vp44? Would the new lift pump be "hiding" the bad vp44 by reading 16 psi? Or would the new lift pump still cause my fp to be low, showing that my vp44 is going south?

The reason I ask is that I HATE not having my truck, let alone letting someone else work on it. I'd rather have 2 birds killed w/ 1 stone, since my truck is already there at the dealer. Thanks for any info.

Hunter

 

It really depends on how long you let the pump run without adequate fuel pressure. Out of almost 50 VP44 pump changes I have done, 70% of them had come in a month or so before for a lift pump change.

Just because your lift pump is giving the VP 16psi, does not clear you from suffering a downed VP. There are more failures that can happen to the VP than just inadequte fuel pressure. But, it is the leading cause.

More than likely, the dealer will not change your VP if it isnt showing signs or throwing codes. Especially in a warranty situation where they have to cover there butt with a paper trail.

 

Glad to hear that they didn't give you any grief. You might ask them to test the VP pump. They have some sort of electrical gizmo they can hook up and tell you if it's working or not. You could also have them pull the codes while it's in there.

 

Make sure I understand your post - do you expect to get 16 psi at idle with a new Carter in the stock location?

Also, I changed out my original lift pump when I got my gauges installed. 6 psi at idle for who knows how long. That was 15,000 miles ago - no codes and same VP.

Matt

 

I ran a comp with the wire tapped for about 10K miles with 0 pressure at WOT. That was 30K+ miles ago. I'm still on the original VP. KNOCK ON WOOD!!

 

All that electrical "gizmo" consists of is a breakout harness for the VP44. It takes every sensor out of the picture and only sends the ground off of the #6 pin, 12v to the #7 pin and a signal to the idle droop. All that you do is hook it up to a battery and start the truck. After the truck is started, hook the idle droop wire to the positive side of the battery, if the truck doesnt idle up, your VP is bad.

Just sheding some light here.

 

I'm hoping for something near that. Anything better than 9 will suit me fine, except 10, 11,12, or 13...hahaha!

 

Get a Holley and be done with it.

 

When I replaced my original lift pump with another one, stock location, and had the Wildcat Flow System on, I got 11 - 12 at idle....

Matt

 

Did they check at the dealer to make sure that you are getting good pressure? It could be a bad pump

 

When I had my stock lift pump replaced, it had 13 at idle and 6 at WOT. When I replaced that with my Holley Black(which I should have never replaced but oh well) I had 17 at idle and 13 at WOT. When I replaced that with a PE pump, I get 19 at idle and 17 at WOT. You see a pattern here?

 

Ok, just picked up the truck and now I'm gettin 15 at idle and 8 at WOT. Yall think that should be higher w/ the new lift pump and high flow banjos?

 

You'd like to think it would be.