i put the truck back to stock, because im sellin it.......and last week my fuel press. droped from 15 idle to 10 and 12 wot to 1-0 and even below....i have a campagin pump(6months old) i first i changed the fuel filter and hooked a guage up to the canaster, same thing. so i bought a new campagin pump.....same thing!!! could it be the pick up tube in the tank or the fuel lines or what? my fuel gauge quit back last spring could that have anything to do with it?

i ran 15 idle and 8 wot with the 100hp's and superchips on #2


edit the injectors are 275's the 100hp's are on the stock bodies.

 

could have a crimp in the hose where you installed the pusher pump, or in could be in the tank, as you said, or you oem pump might be dead and the pusher is having a hard time pushing the fuel though it.

 

Are you running an isolator on your fP guage?

 

no i know i didnt crimp the lines, i replaced the rubber hose, and it shouldnt be the vp it's only 6 months old too. i'm sure there's a sceen on the bottom of the pickup tube, and i think thats what it is. i want to fix it as cheap as possible cause im sell'n it, but i dont want it to cook the vp before of soon after i sell it. i dunno i guess im gonna have to waint untill thanksgivin to work on it cause goin to school and workin 8hrs a night dont leave much time much else. and after i work on everybody else's trucks all day i dont feel like commin home and workin on mine lol


i reckon thats with most mechanics, we work on our tucks last


o well i reckon i'll drive the 92 ctd untill it get it fixed, and hopfully sold, then i'm gettin a old 12er

 

nope, just a ball valve on the vp banjo bold other than the exhaust, clutch, 275 rv's and the fp gauge it's stock

 

You might check the overflow valve on the VP44... I've heard stories of the check valve inside failing and allowing the pressure to flow back to the tank....

 

alright, can ya get a pict or a little better deffinitoin.....

if not i'll look on one thats on a stant at school tomorow........

 

Well when my truck fuel gauge quit the hole sump broke off the mount in the tank and was laying in the bottom. I dont know if this is the problem but when mine was like that when the fuel got low it would start drawing air into the system. Just another idea. Its not even to bad to drop the tank.

 

it's not been below a 1/2 tank in over 6months, my fuel gauge quit so i normly get fuel around 200 or so mi, which should over a 1/2 tank, the pressure is the same regarduless of the fuel leval, because when it stared was last week after filling up and i filled it up tha last day i drove it.

 

Interesting as my fuel pressure also dropped from 15psi to 8 at idle right after i filled my tank last week. My truck is stock and i have a Carter pump mounted just after the fuel tank on the frame rail, it seems to be working ok. My first guess is that mayby my stock pump gave up and it's having a hard time pumping through it. I suppose it can be bypassed all togather?

Bruce

 

[QUOTE=Flyinb;1197550]Interesting as my fuel pressure also dropped from 15psi to 8 at idle right after i filled my tank last week. My truck is stock and i have a Carter pump mounted just after the fuel tank on the frame rail, it seems to be working ok. My first guess is that mayby my stock pump gave up and it's having a hard time pumping through it. I suppose it can be bypassed all togather?

do you still have the lp in the stock location to?


im beging to think that it's something in the fuel thats got either the screen on the pickup tupe cloged or the line it's self, cuz i put a lp on a isb in a freightliner schoolbus a while back and fuel ran out of the line and come to think of it the first time i changed my lp it did too, and this time it didnt....so when i get the chance, prob this weekend im gonna pull the bed and fix it.....hopfully i think in gonna put a new sending unit and mabey a vulcan draw straw, just so i dont have to mess with it again.......+ it it's the pickup tube it aint much more that a oem one, i dont think


unless anybody else has any sugestions........i guess i'll keep yall up to date on whats goin on

 

(do you still have the lp in the stock location to?)

Yes I still have the stock lp in the stock location as well as the Carter pump on the frame rail. So the carter has to pump through the stock pump. How do folks bypass the stock pump? Just cut off the banjos and use a piece of hose?

 

well if it was me id put the banjo fitting with the barb form the inlet of the stock lp on the filter housing and get a peice of longer hose and run it up there like that.


yes i have a single lp in the stock location

 

If it was me... (Just a suggestion here)

I would disconnect the in-tank pump. Or thorw out that in-tank pump and order the old stock fuel sender and pick up tube... It's still available!

Then go out and order a Vulcan Draw Straw kit and Vulcan Big Line Kit (with pump - Carter Campaign, FASS, or Walbro).

Then you'll never have to mess with that junk in the tank for a long time...

 

More info please, I'm experiencing the same symptoms, 16 psi idle down to 10 idle for no reason. yes I have an isolator but I re-bled the entire thing this weekend and new fuel filter same symptoms, couldn't get new fuel fittings on a Sunday in this one horse town for the needle valve I bought to get rid of the isolator.

Thanks