Today I changed out my fuel pump due to low pressure when idling. I checked the pressure again after the swap and this is what I got;40 when priming but then quickly drops to 10 psi then to 0 and then i started it and got 30 psi idling then I disconnected the fuel pressure regulator vacuum line and it only went to 40 psi.I reused the bucket and just glued the top back down.Could my fuel bucket be the cause of this or what else could it be.I checked the fuel injectors for leakage a couple months ago and found no leakage.Right now i am leaning towards a hose leaking,maybe the one that sends the fuel from the fuel pump.Please help with any ideas that you may have Im kind of frustrated with this .Thanks for reading

 

When is the last time the fuel filter was changed?

Did you check the FPR vacuum line for wet fuel?

What does the fuel pressure read WOT/full load/max RPM?

 

The fuel filter was changed a couple months ago and the fpr wasnt wet and the simulated wot pressure was 40 psi

 

What is "simulated wot pressure"? You can't "simulate" the WOT fuel pressure simply by removing the vacuum. You have to have the engine under full load, so its actually consuming large amounts of fuel.

 

I thought simulated wot pressure is when you disconnect the vacuum line from the fpr.I havent checked the fuel pressure at wot, i thought it would harm the engine. Could I still be making good pressure at wot even though idling pressure is low?Thanks btw for telling that you have to check the wot pressure under load

 

If you have low pressure at idle/low load, there might be some risk in taking it to max engine load on the road. You indicate you have 40psi with no vacuum. That's only 1psi outside the GM specs for the system (41-47psi).

If you take it out on the road, take it to 1/2 power first, and see if there is any sign of the pressure dropping below 40psi. If there isn't, take it to max power. The fuel pressure regulator controls the pressure by pinching down on the return flow to the tank. If the fuel pump can't meet the engine's fuel requirement at max power, there isn't going to be any fuel going back to the tank, it will all be going through the injectors. Pressure will drop. You can't "simulate" that by sitting in the driveway.

 

Do you have a metal fuel tank? I had to replace my pump twice before finally figuring out that it was a rusted metal tank that was fouling my pumps out I replaced it w/ an after market place tank has ran great every since my car is 11 yrs old now w/ 185,000 miles and runs like it's brand new.

 

plastic tank sorry not place tank lol

 

From first to last, things that effect fuel are pump, fuel filter, fpr, rails, injectors. Of course hosing that whole way too. I didn't see injectors mentioned anywhere. Are they leaking or stuck partially open?

Any symptoms from having low pressure? Hard starting? Bad idling? Choked WOT?

 

Nothing like resurrecting a 4 month old thread.