Fuel Pressure Flutter

[Bucky]

With normal driving the fuel pressure will stay around 10 lbs. Recently my fuel pressure gauge has started fluttering or bouncing when I accelerate or when the truck is under a load. When it bounces it will go from about 6 to 20 lbs. and fast enough that it is kind of a blur. When I let off the accelerator the gauge is rock solid again.

Things I have tried:
I have connected a test gauge to the schraeder valve on the VP44. (both gauges bounce)
New fuel filter. (no change)
Different lift pump. (no change)
Wired the lift pump directly to the battery. (no change)
Different overflow valve (the banjo bolt that fastens the return line to the VP44). (no change)

Could it be in the VP?
Any ideas or suggestions?

Bucky

 

[Whit]

I wouldnt be concerned with it as long as you stay above 5psi

that overflow valve opes at 14psi.........the VP dont like more than that

 

[JMeier]

I am running 2 lift pumps, one on the engine and a pusher on the frame. I am running about 19 psi at idle and 16 psi WOT. Is that bad on the vp to stay above 14 psi? Could that cause excessive fuel consumption?

 

[Whit]

I have always been against the 2 pump method..........2x as much crap to go wrong

this wont cause excess fuel consumption but do yerself a favor and get a Fass or Airdog pump.......................dont need the filters with em just get the pump alone for around 400 clams

 

[Mopar1973Man]

The only thing I'm going to dis-agree with Whity about is the low pressure point...

For 2nd Gen 24V its 10 PSI

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For 3rd Gen Common Rails its 9.5 PSI

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Both of these images are from the Dodge Factory Service Manuals (2001 and 2003) books...

As for exceeding the 14 PSI... I wouldn't go no farther that 20 PSI...