4doogie

so, i have airtex and a bd inline pump on my 01 and my edge reads between 30-32 at idle.....

is that ok?

i just swaped about 3 lift pumps into it because im trying to figure out my buddys 99 dodge starting problem...: ( we think its the vp....: (

but anyway is 30 harming the vp? at startup its fine, no hard starts, the bd pump doesnt kick on till it reads pressure from the motor... but everyone always says like 20 with setups like mine from what i have read...


now on to the next question, i installed my buddys lp off is busted 99 on my dodge today and started the truck and with my bd pump and his stock lift pump i barley hit 15 at idle.... so im thinkin his lp went low psi on him and his VP died, any way i can tell if the vp is bad? trucks 4 hours away from me and ive already driven to it once to tinker with it.... any ideas guys

DodgenIt

As for the pressure, Im sure someone will chime in that knows for sure, As far as I know it shouldnt hurt anything, Its is possible Im wrong on that though. I myself run 20-21 psi at idle.

For his VP.. Have you checked for codes? Do the ignition trick with the key and see if you get any codes.

Nick02Ram

I've read that's too high. Not sure what the consequences can be, but I've always heard keep it right around 20. And for your buddy, when the VP goes, there's normally a few codes that pop up. Have him check those before ya drive all the way over.

high bid

The key trick won't work on a 99 but most auto parts places will pull codes for free. Fuel psi to the pump is ok at 20psi however your fuel filter housing may begin to leak at anything over that...probably around the WIF sensor or fuel heater. And it is possible for the VP to be going out w/out throwing codes.

BarryG

There are several members here and on other boards who have transplanted a 12v lift pump on to a 24v engine. The pressures are in the upper 30's to upper 40's with no apparent problems to the vp even after 100k+ miles. Keith Locklier of Diesel Dynamics stated in a thread that they had also done the conversion many times and everyone of them is still running fine with no damage to the vp. I am in the process of doing it myself. Putting in a cam now with the fuel pump lobe on it.
However if you are concerned you could install a bypass such as the secondary type bypass shown below
http://www.kinsler.com/Cat_31_High_R..._press0035.pdf
and just plumb into a return line to the tank.

STate

Im not sure if I read your post correctly, but dont you get rid of the VP44 when you install the P-pump on a 24valve??? Doesnt make sense to have both.
Which brings up another question, when you swap in a P-pump on a 24valve, what type of lift pump do you feed it with...a 12valve mechanical pump, or an aftermarket like fass or airdog???

4doogie

well i know the answer to the last question, from what i have read, if your going to do a p-pump convertion it would be easy just to throw a fass or airdog on because you would need to put a cam with the extra lobe in it. plus most of what i have read people say if your going with high HP numbers the mech. 12v pump wont be enough, i have a band new one that i took off my 12v that was used for 2k miles if anyone is interested. i have always figured that with an airdog or fass, ive had both it makes it really simple to know that fuel is getting from your tank to your vp, or p pump really easy, ive never had it fail and its not too hard to install


as for my situation, i know u cant do the code deal with the 99, but here is the sucky part the truck is 4 hours away from us at a vacation house hahaha in lake tahoe hahaha, im pretty sure his LP took a crap and crapped out his VP..... no check engine code comes on tho, she just keeps crankin over with no sign of wanting to start, i think we are going to try and find a trailer and bring it back into town so i can throw a code reader on it and start there.... i just got beat on a brand new HRVP44 brand new no core for 1500 bucks shipped, how lame is that, guy on cummins fourm needed money.

as for the 30-32 psi im seeing with my fuel setup i think im just gonna drive it and then do a bigline kit to try and have a little more volume and hopfully drop my psi down to 25

thanks guys

BarryG

STate:
Yes if you were converting a 24v vp44 to a 12v p pump you would not need both pumps (vp and p). However I am not converting to a p-pump. I am just converting the lift pump from a 24v electric to a 12v mechanical still using the vp44 as my injection pump. I think I have read that the 12v lift pump is good to well over 600hp, I am only around 400hp.

4doogie

yea the 12v mech. pump is a solid pump, they are extremly rare to go out, the guy i bought my 94 from thought the cam lobe went flat hahahaha got it for 2500 bucks, he replaced the mech. pump and i switched to an airdog on it for other reasons. but if u know anyone i have a mech pump thats pretty much brand new.

Fishin2Deep4U

30 PSI may result in hard starts, but there's no evidence it'll hurt anything.

I also run a 12V mechanical lift pump and I see mid 45psi idle, 37psi WOT.

Dave