Engine/Transmission (1998.5 - 2002) Fuel Pressure

[Wolfgang]

I have Briar Hoppers test gauge and had been checking my pressures at the access port off the VP44. these were 3WOT, 13 at idle. I told my local dealer this so he replaced the lift pump no questions asked. After I got it back the pressures hadn't changed then it started starting hard.



This morning I checked both before the filter and at the VP44. Pre filter it never goes below 8 psi. After it goes to 3 still. Does this mean I have a clogged filter and could that be the reason that the truck starts hard after sitting awhile.



Two months ago I also put in new dd2's. The hard starting problem started about two weeks after the lift pump was put in and a month after the injectors were installed.



Sorry about the length of this post, I took it to the dealer were they had it for a week and a half to fix the hard starting (replaced the fuel lines) I don't want to take it back if I can help it.

 

[rspinks]

If you've got 8psi on the fuel filter inlet and 3psi on the outlet I'd say change it because it's plugged. This could very well be the hard starting problem as well. How many miles on that fuel filter?

 

[Wolfgang]

5000 miles

 

[Whitmore]

#1 rule

always carry a spare filter or 2 and also have a filter wrench... ... . this is only just incase you get a load of bad fuel.



I change my filter at 10 k but always buy from the same place and have had good luck so far

 

[zimman20]

Wolfgang- What the others said, sounds like a clogged filter. Also remember to buy your fuel from a reputable, BUSY

dealer, indicating a high turnover and fresh fuel being delivered to you. That being said, even busy dealers can get a bad load of fuel or run their tanks too low and start pulling crud off the bottom of the tank (happened to me one time filling the fire truck, full tank of damn near water from the township garage and the truck was DOA at the pump before I could pull away).



If you change your filter yourself, make sure to drain the filter housing and clean out any crud at the bottom before reassembly. Good luck.



zman

 

[Wolfgang]

Well changed out the filter this morning no changes to the pressures. Any other ideas. I would have thought that should have taken care of it. Still starts hard

 

[Whitmore]

Wolfgang

I had the identicle problem after I changed my lift pump too, heres the deal , inside the internals of the oem pump there is a spillback from the discharge of the suction of the pump that has a little spring and check ball, the purpose of this is so the pump does not dead head and burn up, pressure is what lifts the spillback into play. What I did was added some stanydine as I always do and babied the truck for about a hundred miles and whenever my psi gage read good I would get it on, and when ever it showed low psi I would babie it as not to let it get below 3 psi ever, pretty soon it shaped up and has been fine every since then.



In other words when you are seeing the psi to be low that means the spill back is open... ... ... . Kevin

 

[Wolfgang]

Whitmore I'll try that. Thanks.

 

[Ron Bissett]

Low Psi after pump change?

Its possible you got a bad pump and possible the wrong one not the latest ,mod , if Dodge stock number should end with AA ,if from Cummins should end with 5 . Looks like a trip to the dealer again. LOL Ron Bissett in LOUISVILLE KY. Oo. Oo. :-{}

 

[Smills]

does anybody know where the info is on testing the lift pump weather you check it under load or no load.

thanks

shane