http://www.youtube.com/watch?v=NL6d3y_JEz8

i just bought this truck never working on diesels and i have been lurking and reading these forums to figure out how to solve my dead pedal issues...so far here is the info on my truck...I have done all the work myself i am a mechanical engineer so working on things comes easily

-2002 dodge 3500 6spd HO model
-Fuel pressure and Boost pressure gauge
-Brand new factory lift pump
-Brand new turbo tim APPS sensor
-New fuel filter
-Fresh rotella 15w40 with k&n filter
-101300 miles
NO CHECK ENGINE LIGHT NO CODES CHECKED WITH SCANNER

HERE ARE MY SYMPTOMS:
When my gas gauge is full the fuel pressure stays steady at idle but when i get on it just slightly it drops below 10psi and sometimes as you can see from the video when i hit 18 psi boost pressure the fuel pressure reads 7 psi ...doesnt seem okay for the injection pump because before I installed the APPS sensor and the lift pump my check engine light was on and read four codes the po216 the transfer pump low circuit code and the apps low circuit code. After I installed the new lift pump and apps sensor all the check engine lights went away.
SOoooo when i start the truck it smokes white and studders a little bit...but the weirdest thing is when i hit just below a quarter tank the fuel pressure fluctuates like crazy and the car has died but then after waiting 7 minutes it starts right back up but only after 7 minutes otherwise it justs cranks even with the new lift pump


I am almost positive i need a new 028 Vp44 injection pump but what my question is
IS THIS FUEL PRESSURE NORMAL IN A LIFT PUMP OR SHOULD I INSTALL A RAPTOR OR AIR DOG TO GET MORE FUEL PRESSURE????

 

The 7 psi would make me a little nervous also. I had a lot of flucuation in pressure on my truck also. Come to find out it was the connection to the T where the return line connects was loose and I was losing prime after my truck sit awhile and was get air in the fuel system. After tightening it up thing are back to normal. Have my pressure regulator set at 16 psi at idle and it doesn't fall below 12 psi at wot now. The air in the fuel system will also cause an injector pump calibration error code to pop up.

 

is there a factory adjustable pressure regulator? or is that aftermarket?
so you are saying i should try tightening the return line to the truck...and what if the spring in the return line fitting is bad? should i pull if off and check it to see if i can hear a rattling inside it maybe indicating a broken spring in side the fitting??
thanks for the quick response but i still have soo many questions

 

i am havena problem with my lift pump my truck is surgeing and backfired...?

 

No, chances are your overflow valve is good. Follow the return line to the back of the engine to a T and see if it needs tightening. The pressure regulator is aftermarket and I'm using it with a walbro liftpump that pumps up to 95 psi. This is the reason for the regulator.

 

okay i will try that thanks!
any other suggestions as to why my fuel pressure could be soo low?

 

Nothing more other than the fact it's a factory lp and if it's still mounted on the engine it is destine to fail due to heat and vibration. Also being on the engine it's having to pull fuel all the way from the tank. A pump can push fuel a lot easier than pull, that why your aftermarket pump are mounted back on the frame closer to the tank.

 

My "factory" Carter lift pump puts out 11-12 psi at idle and drops to around 7 psi under part load. At WOT (wide open throttle) under load it's around 5psi, it's been like that since I put it in a few years ago. I think that's normal for the engine mounted "factory" style pump.

 

**** i am buying a raptor tonight i figured this is what the factory operation is like and its no wonder why the injection pump dies soo quickly

 

I just ordered a raptor along with a new injection pump...thanks for all of the help
this forum and the people on it are awesome I have just been reading and reading and searching this forum and it has pretty much taught me everything i need to know and do to work on my truck myself
thanks again! diesel truck resource!

 

While your at it I'd check out the Vulcan Big Line relocator kit. I don't know what comes with the Raptor system....

http://www.vulcanperformance.com/category-s/182.htm

 

Here is an idea to think about. You prolly will not try this because it is just too easy, cheap and simple , but who knows you might . Try using some Howes in your fuel. It helps get the crud and possible water out of the system. It has worked twice for me now when my fuel pressure dropped real low. Then like two weeks ago my fuel pressure had dropped to 13-15 psi because I had not added some Howes for four tanks of fuel, so I added some Howes and I was right back up to 15-18 psi. Seems to happen more with winter diesel fuel.

 

Don't be fooled by the CEL going out. You have a dying VP-44. They often live a long time after starting to act up but sometimes just die and never work again. I had one that survived for 6 months at about 60% flow and never threw a code.
And yes.... even with a healthy VP-44, fuel pressure will drop at heavy throttle.
With a new VP-44 it will only drop to 11 psi +/-.

If any plans to add some HP down the road, I'd recommend a 027 VP-44. Flows more fuel.
If staying stock.... you do not need the raptor or the AD.

RJ

 

My stock lift pump acted about like yours. AirDog idles at 15 & drops to 12 at WOT. Have the tank supported off the ground when you install the draw straw. Otherwise, the bottom of the tank can be pushed up & you'll install the straw too high in the tank. You can pump air when going around a corner with a low tank.

 

First time I've heard that?? Seeing how the tank straps support the tank from the bottom also...not sure it's a serious problem.
I did mine sitting on the ground and have had no problems.
Cut end of the straw at a 30* angle and installed it touching the bottom.

But I never go below 1/4 tank unless on long road trips so maybe I don't really know?

RJ