Fuel Pressure Issues

[whiner]

So last night I put another Walbro fuel pump in the GN. Car still runs horrible.
I have 50 psi of fuel pressure at idle. A brank new adjustable fuel pressure regulator & I can only adjust the fuel pressure about 4psi. The fuel pressure drops to zero as soon as you turn the key is off. Key on and not running it goes up to about 20psi and then drops rapidly. Any ideas. There are no kinked hoses. The fuel injectors and fuel filter are new, also had the tank cleaned out at the same time & all these only have less then 200 miles on them since installed.
When I installed everything oringinally I could adjust the fuel pressure to 42psi line off & the car ran better. It just keeps getting worse.
It will stuble off the line and stumbles at boost above 6psi. Also idles like crap. I do have all new vacuum lines and intake and intercooler hoses are all
new and not leaking.
Any ideas???

 

[Phoneguy]

Sounds like you have a bad FPR or one or more injectors stuck open. Check your injector harness for bare wires.

Bryan

 

[whiner]

Replace FPR and there was no change.
I was wonder if I had a bad injector. The injector harness is new when I did the injectors.
How do you test for a bad injector?

 

[Tom Tom Turbo]

you've probably done this already, but are you sure you don't have a leak somewhere, like an o-ring on one of the injectors, regulator, or feed line? With the key on but not running I would think the pressure should hold if the pump is good.

 

[whiner]

I may have a leak at one of the injectors. There is no gas leaking, so I think that it is internally in one of the injectors. Only thing is how do you test them or find out which one it is?

 

[Clark6]

Are you sure you don't have any lines crossed? input to the output on the fuel lines or vacuum in the wrong place or disconnected ?

crank the car and unplug the cam sensor to rule that out just to be sure, and see how it runs. Then get back to the fuel lines once again.:smile:

 

[etriebe]

Pull the plugs and see if any of them are soaked. if all are good try pinching off the return line, turning the key on and see if it holds pressure, if it does you know that everything from the tank to the injectors is good. If it doesn't hold you have a problem before the return. I have recently had a bad fuel pressure regulator, crimped off the return line and when I took the hose crimper off everything worked great just the regulator got stuck open causing a hard start.