Engine/Transmission (1998.5 - 2002) Chirping Fass Pump

[BEmmert]

Anyone have a fass pump that chirps and over all makes inconsistent sounds when the pickup is sitting at an idle? I would think this pump should sound smooth and consistent, but is not. 98. 5 24 valve, Diablo power puck and 35 hp injectors. Nothing extreme or real fancy and the pump is the HPFP 95 Fass. Has been on for about six months now and started to notice it doing this, seems that when you grab hold and move the wires around some leading into the pump itself it will smooth out and behave. Replaced the two prong connector unit in hopes it was finding a loose connection there with no change in behavior. Went so much as to put all new filters in again and blow air in the lines into the tank to make sure nothing was obstructing it with no difference so electrical is my guess at the pump itself. Ideas would be great if this sounds like it’s a problem. I don’t know the pump pressure as I don’t have a gage for that, but I do have the dummy light on the filter housing and it has not gone off yet while it is running.

Thanks

 

[CJNielson]

I have had a similiar issue. Not FASS, HPFP. The pump will seemingly randomly start running inconsistently. Sounds like the pump is straining from time to time, fuel pressure drops a few psi. I have had it happen twice where the pump has shut off... ie zero fuel pressure. I have not had any additional issues. Turn truck off, and back on and it runs fine. I have changed the filter at these times with no difference.

 

[BEmmert]

Fass ended up replacing mine as the wire conections were bad on the motor.