I've been having issues with fluctuating fuel pressure on start up ever since I installed a new VP44. Not all the time, but a few times a day I will start the truck and the FP will be around 10 PSI (normal is 16 PSI). If I put the truck in drive it with the FP at 10 PSI it will die. If I put the truck in neutral first the fuel pressure immediately comes back up to 16 PSI and then I can put it in drive and no stalling.

What would cause the fuel pressure to change just by putting it in neutral?

FASS HVLP pump.

Ideas?

 

Really, should not be anything to cause that. Could be something with a ground fault I guess.

Dave

 

I'm scratching my head too. I can't figure out how putting the truck in neutral would change fuel pressure.

 

Check the pressure coming from the fuel filter. Had a similar problem with my FASS, dual filter, 150/150. The first filter visually checked out, but something in it wasn't allowing the fuel to flow while meeting the demands of having it in gear. Do a fuel flow check.

 

Electrical or mechanical guage?
I've seen electric one thet were very sensitive to voltage.