Mopar1973man

One of the two things are occuring (or both)...

1. You fuel lines are too small to supply the volume of fuel your VP44 needs for WOT operations. This usually shows in a big loss of pressure. Be sure you have large fuel lines all the way to the tank. 3/8" lines are OK but 1/2" lines are even better.

2. You LP pump cannot pump the volume of fuel required by the VP44 under WOT operation. So once again your seeing the pressure drop because of demand of fuel is highier than the supply of fuel.

caleb

427ac you onlt upgraded from the filter housing to the VP44? If thats all you did and your still running a stock LP only I would say that you are getting great pressure for stock. Nothing really to worry about

C Schomer

I'm learning a lot! I discovered my bad LP today. That inline valve on the Glacier setup is probably a PR valve (pressure relief) if it's teed into the pressure side of the pump and returns unused fuel to the tank. That's the best way, instead of short cycling the unused fuel thru the pump and building heat in the pump. The Campaign pump sound darn good to me - for ~$47! Craig

dodge lightning

I am runing a new in-tank pump and the origional one in the stock location and i have 21 psi at idle and 18 at WOT is this too much? 99 dodge 3500 4x4 5 speed. edge comp

Mopar1973man

I know the the minimum is about 8-10 PSI...

But I wouldn't push much over 25 PSI... I've seen a few as high as 25 PSI but I'm not sure how long the pump will last and that pressure...

The overflow valve is suppose to open at 14 PSI and dump back into the return line to the tank... So anything higher that about 15 PSI is being return to the tank...

dingoe

I’m new at this so forgive any dumb questions, but I though the failure in the VP44 was in the diaphragm and it cracking due to pulling to hard when the stock LP is low on PSI. If so pushing 18PSI or higher sounds like it would be too much and if you had cracks the VP44 would fail or would you just push more fuel through and have more return?

Sounds like one big improvement would be just to dump the banjos and run new larger line from the intake of the LP on to the vp44, or is the lift pump still too weak due to location (not close to the tank) and heat buildup?

Now what about the hookups if running the stock LP and the new Carter or Holley or other back at the tank, do you piggy back into the connection on the stock LP or will that not supply enough for both pumps? If your running a stock truck are two pumps really needed, or is 15 ideal for stocker? Sounds like Mopar173man and others are running BOMB’s and getting by with one and ½” lines. What is that on the connections 4an or 6an, I guess stock is 1/8” or 2an??

Can the Carter Campaign run at stock LP location? A $50.00 backup sounds good.

supr

The Vulcan Big line kit moves the LP back by the tank & removes the old small fuel line & banjo bolts. Also, if your LP craps out, you can easily change it in 10 mins., maybe 5. No hot motor to contend with. I run 12.5 PSI with the Vulcan, most run 13-14. At WOT a liitle under 10.
The campaign pump from Cummins at $65 seems to work better, no complaints that I have seen. At $65, you can afford to replace it every year or two.
Not sure on the other questions.

dingoe

Any reduction in MPG with the Vulcan stock LP or Camaign at tank?

supr

You may find that your truck uses more fuel if it is not in the shop getting the VP44 replaced.
No change in MPG. It just makes sure you VP44 is well supplied with fuel.
Lots of happy users on this site. Just search on Vulcan. About $125 for the kit. very Professional kit, excellent intructions.
The Vulcan has a port down stream from the FF to hook up you gaige. Very nice!