fuel pressure question

[bigblockdsm]

I have a 255 fuel pump with 550 injectors, at a idle the fuel pressure is at 45 - 50, on the dyno today the car was lean and would not make any power. The fuel pressure didn't move when it was in boost. Another werid thing is the fuel pressure drops completely when i turn the car off, and when i start the car it doesn't start right away. I checked for leaks everything seems to be ok What could this be?

 

[L2RTSiAWD]

Sounds like your FPR is bad.

 

[L2RTSiAWD]

Moved to problem diagnosis.

 

[bigblockdsm]

Moved to problem diagnosis.

you know something i have the b&m fpr, but i put the stock regulator and it still did it ??

 

[eclipseyou]

sounds like ur fuel pump is hosed or you have some kinda fuel blockage...because I have a
255 walbro fp and 660cc injectors and they are overrunning my stock fpr...so I actually have to turn down fp for idle....

 

[1LE]

Perhaps a blockage in the vacuum line to the FPR? I've been getting a EGR CEL for awhile, pulled stuff apart and found a small screw stuck in one of the vacuum lines!

 

[bigblockdsm]

Is the fuel pressure supose to drop when i turn off the car ?? shouldn"t the fuel pressure rise as soon as i turn on the ignition ?

 

[1LE]

Shouldn't drop when the car is shutoff, but mine does and it doesn't hurt anything. Just means that something isn't holding the pressure (probly the pump) when off. I don't get pressure until I attempt to start the car. Turning the key to "run" doesn't seem to be enough to kick the fuel pump on.

 

[bigblockdsm]

Shouldn't drop when the car is shutoff, but mine does and it doesn't hurt anything. Just means that something isn't holding the pressure (probly the pump) when off. I don't get pressure until I attempt to start the car. Turning the key to "run" doesn't seem to be enough to kick the fuel pump on.

i took the pump out today and it seemed that o ring was not seated properly, if thats not seated properly it will leak, and not put out enough fuel. when putting the assembly back together the pwer wire broke off :thumbdown. If there was a leak somewhere else i would most likely see it.