Fuel pump problem on 2008 Z1 340 HP

[Frank158]

Last weekend my engine started to loose power and backfired.
I checked/cleaned the fuel filter and all electrical connections on the engine, couldn`t find anything wrong. Exept the running time of my fuel pump, it used to run 3-4 sec. now it runs 10-12 sec.
Pls. Help

[chpthril]

Back firing is typically an ignition problem, but the fuel pump will run for about 5 seconds and shut off when the key is turned on without starting the engine. It does this because there is no need for fuel, if there is no ignition input. The pump will run continuously when the engine is running.

[Frank158]

Hi chpthril.
The high pressure fuel pump runs for 10-12 sec. as soon as the ignition is turned on without having the engine running. It used to be 4-5 sec.

[Frank158]

What´s the fuel pressure with the engine running in idle? Get only 28 PSI

[River Runner]

I believe fuel pressure should be 35-40 psi. Does it act up only when hot?

[dogbert]

Might want to check for obstructions at the tank end of your fuel line. Also, backfiring could be caused by bad gas.

[brody66]

Check you fuel pressure regualtor, not sure exactly where it is located on your engine, most likley on the intake, but if you pull the hose off the top and fuel drips out it needs to be replaced, if nothing comes out then thats not the problem, this is very common problem on the earlier 5.3 vortecs in gm light trucks.

[Frank158]

Boat is running changed the high pressure fuel pump and filter. Got 60 psi fuel pressure now.