strokethisgoat

If you got the little 35gph pump from the hardware store, your wasting your time, if you ever make any modification it will end up restricting fuel rather than helping supply it. The orfice inside that little pusher pump is way too small for much fuel to go through. I found this out......

motomac3

well like i said in the original post this is by no means a permanent solution. just something to give me plenty of fuel till i figure out which way i am going to go. i am no mechanic but can do a fair amount of work since i wrench onm my rock crawler all the time. this ctd is new to me....only had it 3 weeks now. i will eventually build my own fuel system with bigger lines and a big pump...just not sure how i will do it yet.

AlpineRAM

The VP44 without a lift pump is used on engines with less than half the displacement per cylinder than the CTD. Those engines do rev much higher and inject much less fuel per revolution than our engines. Therefore the relation of fuel injected to fuel used for cooling and lubrication is much worse for our engines than what the VP44 was planned for. Since a lot of us do install devices that will further increase the amount of fuel injected for a given rpm we are running the VP44 to it's ragged edge - Therefore IMO it is beneficial to supply enough inlet pressure to avoid cavitation and other issues.

Just my 2c

AlpineRAM

Sunir

good thread...I was also told that lubrication is what the VP wants/needs. To that end would adding a fuel additive with lubricity enhancement help the VP44 issue? I'm going to put a FASS 95 gph kit (150/95-1008) on very soon, just wanted to know what else I can do to help the VP44 do it's job and not die.

bnold

I have the ability to just pull a fuse and go from 11psi at idle to 24psi at idle... at 24psi my pressure never drops below 19psi. Ever...

A test would be cool to check multiple points of temperature on a hot engine to see if the extra pressure (maybe more flow maybe not), has any cooling effect on the VP.... Would also be cool if somebody tapped a temperature gauge in the return line from the VP to see changes in fuel temperature...

As it seems a lot of VP failures are due to electronic issues, and electronics are so sensitive to heat, may be good tests...

mini14

i ran my truck for 7 years @or<5 psi, as long as the vp gets at least a minimun of 5 psi at all times u wont have a prob.

motomac3

but if you could hae 15psi for 50 bucks wouldnt you? i for one dont like flirting with minimum's. if they say i need a minimum of 5 i dont want to get anywhere near 5 becasue then i would be at the bare min. it needs. might as well have more than you need and the "peace of mind" that you are doing everything in your power to help the vp live a long and healthy life.

duner

http://www.bluechipdiesel.com/inject...pfailures.html

motomac3

wow.....great find!

saab9k

this what i have, with a bypass regulator, solid 17 idle, 15 wo.

First pump is stock carter, second Holley blue alike, $ 59.

checked, each pump by itself, will do 11 - 12 lbs, so if ( when ) quits, it will show on gauge, + have low fuel light there will shine at around 5 - 6 lbs.

almost bullet proof and fairly decent $ price.

A $600 pump can fail too.

Busboy

TSB 14-002-03 tests the flow of the transfer pump, flow being volume not pressure. The criteria for changing the LP pump is flow less than 1.33 L or 45 fluid OZ over the duty cycle of 25 sec of the LP pump. High pressure does not necessarily equal high volume. By monitoring fuel pressure should a pressure drop happen you would then do the volume check.

saab9k

Checking the pressure at pump, there have to be volume to create pressure.

2 pumps, pressure regulator, then 6 - 8 feet of 3/8 hose to fuel filter, 3/8 hose to vp44, where fuel pressure is measured.

The filter, vp44 and return line is what creates the pressure at pump, wo more fuel used, that is why pressure drop 2 lbs, what is fully acceaptable.

1BAD4X4

Thats the set-up on my truck as well. Been running that way for 2 1/2 months now with no fuel issues what so ever.

Busboy

Going by what the TSB says, so long as you have more than the minimum amount of flow the pressure doesn't matter. As it's easier and cheaper to monitor pressure rather than fuel flow, watching for an abnormal change in pressure should point us to doing the flow test. Save our VP's..