I have a DiPricol FP gauge hooked up with Rod's stainless line and also the max flow kit.

This problem has gradually become worse over the past few weeks. It started with the pressure bouncing only while the truck was idling; it would bounce between 6 and 13+ PSI. For a while, I saw a solid 12 PSI while cruising, but now the bouncing occurs all the time, although it is less while cruising.

I first had this problem a few months ago and ended up replacing the lift pump along with the wiring harness. The problem went away but obviously it has returned.

Is my lift pump dying already? It only has about 10K miles on it.

Thanks.
Russ

 

This is going to sound too simple, but change your fuel filter.

 

If you are having the problem that I think you are, it is not a problem, just annoying. The VP44 is tough on gages, it vibrates constantly. When you install a new system there is air in the feed line to the gage, that cushions the gage and it reads accurate. As time goes on it gets straight fuel in the line and starts to vibrate, like you said, first at idle.

If you can make a loop higher than the engine in the feed line, I ran mine over the master cylinder, it will keep the air in the system and will be smooth.

To get it smooth again, disconnect the feed line at both ends, blow through the feed line from the gage end. Hook it back up and it will be smooth.

 

Are you using a needle valve?