Engine/Transmission (1998.5 - 2002) rough idle after lift pump replacement

[DerekUtter]

Replaced lift pump in my 99 2500 4x4 with relocation kit all from Geno's pump is new FASS DDR. No upgrades to truck. At first trk idled fine but now has a rough flutter to it. When raise rpm it goes away but resumes as soon as let off pedal, also seems to go away when put into gear.fuel filter is new. All hose connections are tight and leak free.this never happened before.getting 20psi on pressure gauge with new pump which I have been told is normal for new Fass ddrp. Pump is outside of fuel tank with pre pump inline filter.

 

[DAN V]

Sounds like you might have a clogged pre pump filter.

 

[JR]

Try lowering the pressure by a few pounds. 20 psi is on the high side of where you want to be.

 

[DerekUtter]

Unfortunately the pump is not adjustable.My dad runs the same pump on his 2000, 2500 with no problems.

 

[klcammie]

How many miles after install? Could be some air still in system.

 

[DerekUtter]

About 55 miles on now I did replace pre filter just incase, that didn't fix it. Going to bleed injectors