Engine/Transmission (1998.5 - 2002) fass ddrt lift pump

[dj]

I just installed a fass ddrp lift pump on my '01 245hp truck. On start up the pressure is 20psi at idle. Is this pressure to high? Is the fass pump pressure adjustable? From what I have read, it should run about 16psi. My dash gauge is electrical and I have also checked pressure with a direct reading gauge. They are within 1/2psi of each other.



dj

-- email address removed --







Quad cab w/ camper shell; 245 hp 6spd; modified exhaust; air horns

 

[BDaugherty]

I've installed a couple DDRPs on other people's trucks and they ran 15-17 psi at idle. However, a buddy of mine installed a DDRP on his and it struggles to maintain 12-14 at idle and he's thinking of swapping it for an Airdog Raptor due to low pressure under driving conditions. While I haven't had any trouble at all with the ones that I have worked on, it seems that the quality control over the DDRPs is a little slack. That's just my $0. 02 based on personal experience with 4 pumps and some reading on here.



Back to your real question. I wouldn't worry about 20 psi at idle. Under driving conditions it will probably be lower. My Walbro system runs 19-21 psi at idle and 19-20 driving. I've been running it like that for a couple years and haven't had any pressure problems yet.

 

[DEWright]

no need to worry. My original ddrp was running 17 psi at idle and would drop down to 6-8 a wot, I changed everything in the world out to get to the problem and finally changed out the spring in the ddrp and brought the pressure up to 22 at idle and 14-15 at wot. All seems to be well. If the pressure is too low, pull the spring out of the pump and stretch it out. If the pressure increases then call the ddrp rep and have them send you a stronger spring. It will definitely increase the pressure.

 

[VolsFan]

mine runs 20 at idle and the lowest I have gotten it down to is about 10 psi. Has been running fine for almost a year now.

 

[DEWright]

pull the spring out and stretch it out. If the pressure comes up, then call fass and they can send you a stronger spring. the spring is located under the plate that mounts the pump to the mounting bracket. Piece of cake. That is usually the problem with their pumps. The change out is very simple and you can shake and bake with about 22 psi at idle between 15-20 when running down the road and 14-15 wot. Good luck!

 

[LowFly]

Just as everyone above me has said... ... if you stretch the spring and it fixes your issue give us a call here at FASS and we will get you fixed up with a stiffer spring. Good luck and let us know whats going on!