Guys I need your help. In the mornings or after a long time sitting I am getting very wierd fuel pressure flucutaions on my fuel pressure gauge.

At start up fuel pressure goes to around 13 to 15 lbs. Then will drop to 5lbs. Will jump up and down. Start to drive in city and pressure stays at around 13lbs. Let off pedal gauge drops to 5lbs. As the truck warms up and the more driving I do the pressure will stay steady.
Some reading I have seen. This is after the truck is warmed up. At idle 11 to 13 lbs. WOT 9 lbs. cruise 13lbs.

What is happening here. Is it time for a new lp? I have replaced the fuel filter just to make sure that was not the problem.

Also I am out of the warrenty period by 45 days and Dc says they will not cover this. Just had lp replaced by DC 11 months ago. Thought they may be forgiving but I guess not.

So if it is time for a lp should I go to Cummins and get one or does anybody else make a good replacement?

Thanks Guys for any help you can give.


Thanks,
Artman1308

 

Sounds like either the IP is starting to act up or IP is gone and LP is on it's way out. I don't know much about replacements from places other than dealer. We just had our replaced when we got our truck.

 

Mine did the same thing. So I bought a New Carter fuel pump from Summit. It helped a lot for a while then it started doing the same thing. So I now have ordered the FASS (625.00 with tax). And will expect no more problems I should hopefully have it by the end of the week. DPP is low on them. Change your fuel filter it will help for a while. The Fass is supposed to be the top of the line and carries a four year warranty. It will also allow you to get some big injectors and a fueling box.

 

might start by checking out fuel pressure gauge--lines---isolater ect. --i have been expeirencing similar fluctuations in gauge readings and my pumps are fine ?

 

This is why you have a guage. It is telling you your LP is shot.

 

my gauge has been giving me erratic readings for a year plus---sometimes it works good most of the time erratic
Truck runs great

 

Your truck can run great for a year (with a dying lift pump) until the lack or cooling and lubrication burns up your $1,600+ injection pump. What is the sence of having an FP guage if you are not going to use the readings to monitor the performance of the fuel system?