RowJ

Thanks again...missed that one too. Apologies to all for wasting space here! I guess it's time for reading glasses.

RJ

ramlovingvet

On the same topic sort of. Has anyone added say a Holly Blue by the tank and left the old LP in place?
Pros? Cons?
Thanks

HOHN

I used to think this was true, but my 02 lost the IP (the expensive one) at just 40K miles. It always had perfect FP, and I used lubricity enhancers. It was a mystery to me when it went out, and now I'm paranoid about tapping the VP.

jlh

CTD NUT

I would have thought this would have made you less paranoid about tapping the wire.....now you have seen for yourself that failures occur that have nothing to do with LP fuel pressure and the mechanical part of the VP. Tapping the wire stresses the vane and pump body causing a SLIGHT warpage in the pump body to vane/rotor tolerance because of the large increase in solenoid duration - the solenoid stays open longer during 1 revolution of the rotor to pass more fuel through. On the early VP's the tolerances were supposedly too tight and did not allow for adequate lubrication - these pumps were doomed from the beginning.....installing a wire tap box merely precipitated an existing problem. When these pumps failed, they did not give a 0216 DTC and continue to run - they seize solid and snapped the pump shaft....failure was immediate and without warning - no codes no nothing.
These early VP problems appeared to give the wire tap boxes a bad rep because a box would get installed and the VP would last 20 minutes so the box was blamed.

These failures had nothing to do with the 0216 DTC that indicated VP44 ECU/PC board failures....this is another problem altogether and does not appear to be related in any way to solenoid control and the mechaincal part of the pump. As you know, you can have perfect FP and run all the lubricating additives and still experience an electronic failure because these do nothing except to help the mechanical part of the VP.

So, tap that wire!!

nitrousn

travist is there a dodge tsb on the conversion?

screaminbanana

Here is the TSB site for the 1998, havent seen it there. Didnt see it on the system at school either (lincoln tech automotive).

Moving the lift pump that is supposed to push not pull fluids from every thing I hear works great. I am doing it this week after school, along with a gauge install. I am going with the Carter pump and adding an after market fuel filter as well. Here is a decent set up by njoverkill http://xj.cdevco.net/auto/fuelsystem/ only thing he says he would change and that I am going with is to avoid the gravity feed. I am going to mount the new fuel lines off the stock plumbing coming out of the tank.

TRAVIST

No TSB that I've seen yet. Not to say there won't be one I just have not seen anything on it yet. There is just an update in our cataloging showing that there is a conversion available to move the pump into the tank like the late model 3rd gen trucks. If your interested PM me and I will get you the part numbers needed to complete the conversion. My tech just got back from deisel training and they were talking about the conversion there. The instructor at the training said that the new set up has three times as much pressure as the old lift pump set up. MAJOR IMPROVEMENT!

mamm7215

3 times the pressure, that's about 40-45psi. I thought we weren't supposed to feed the VP44 with more than 20-22?

paulb

You'll lose more sleep worrying about if you should tap the wire, then you will worrying about the IP after you tap it. Sooooo..... TAP THE WIRE!!!

Paul

Forrest Nearing

and that's because they go often...

how often do you hear about a 12v lift pump or p7100 taking a dump? never mind multiple failures on a single truck!!

Joe Diesel

well I went to the dealer yesterday and all the way there idle was 5psi ....as soon as I hit traffic about 3km before the dealer the pressure when back to 15@idle i just cant win with this one

TRAVIST

Sorry guy's I miss quoted what my tech had meant to say. The pressure on the new pumps remains close to the same however the volume going to the injection pump is about 80% more than the old stock LP. We just completed a conversion on a 2001 and it went slick. The wiring was simple and installing the pump was a breeze by just lifting the front of the bed up.

TRAVIST

Mike D

I read somewhere that guys were seeing around 10psi at idle and 3 psi at WOT.

Shawnntx

I heard that the pickup tube in the fuel tank can fall to the bottom of the tank.Where it can suck up trash , grit, sand or other debris.The screws apparently rattle themselves loose allowing the tube to fall to the bottom, where the srceen rubs through rather qiucky then enters that trash through your entire fuel system.Then the damage starts first at the lift pump.

Gear Poet

The LP's checkball and seat is trashed. That's the most common failure in those units, and it's why the pressure varies like that. I had one that idled at 5 psi and gained 10 psi every time I stepped on the accelerator.