Engine/Transmission (1998.5 - 2002) Fuel pressure "buzz"

[Texas Diesel]

My gauge "buzzes" with the rapid FP variations I get. PIS drops to 7PSI at times and a snap on the APPS pedal and back to 15PSI.



Been this way with 3 different LP's and OEM fuel lines and a Vulcan big line kit.



I even hardwired the LP to the battery to rule out voltage varitations, same old BS.



Tomorrow I put the snubber back to quiet the gauge down.



Tried a clear line to check for bubbles, none. Same full or empty.



Tried a new bypass regulator at the VP, no change.



Pressure is constantly varying too, even on level ground.



Just about to go mad or get a common rail ( already looked at an 06 auto 3500 DRW)



Possible the vane pump inside the VP is messed up?

 

[Bob Cochran]

Okay went through the same thing with the same symptoms as you described. I was told the overflow valve could cause this and replaced with a new one, did not fix it. Finally replaced the 10 month old pump(I hated to give up on it) I had purchased from Cummins with one of my two campaign pumps and it is now gone. Hope this helps.

 

[Texas Diesel]

Ok, I have one more new LP, I'll try it and let you know what happens. Thanks