2nd Gen Non-Engine/Transmission Fuel Pressure Flucuating - FASS or VP44

[Hardegger]

Fuel Pressure Fluctuating - FASS or VP44

Last weekend after filling up with diesel my truck wouldn't start and it seemed like it wasn't getting fuel. I tapped the starter and the pressure would only go up to 3-5lbs. Then I backed off the 1st injector line and saw that it was getting fuel, fuel pressure went up to 15 and it eventually started. Now i had the same problem with it not starting but was able to get it started. On a 50 mile drive today i noticed 3 or 4 times when the fuel pressure was running at 15lbs it would all of a sudden drop to approximately 3lbs for a few seconds then climb back up to 15. I'm trying to determine if i have an issue with my FASS system or is my VP44 on its way out. I measure the fuel pressure just before the VP44. Any thoughts?

 

[DavidC]

I would say Fass. Should have constant pressure. You could have a wire issue either to the Fass or pressure guage system.



Dave

 

[DLBurns]

My FP had been rock steady at 15 PSI after the FASS install, last trip it started out fluctuating between 12 & 13 PSI. After about 50 miles it was back at 15 PSI.



Never been as low as the readings your seeing though?

 

[Gary - K7GLD]

Might check for proper, steady voltage right at the pump - bad connectors are sometimes a problem, and the best pump in the world is no better than it's power supply...