Fuel Pump Issues

[Patrol308]

Hi i was wondering if any one could help me i have a gq patrol with a vr 5litre in it and it keeps blowing the puel pump after 1 - 3 months. I have tried 2 internal vr pumps i gu 4.8 litre pump and also using a pre-pump to a swirl pot then a vn 5litre external pump drawing from that and feeding the engine and they all died except the pre pump... but they dont fully stop they just cannot supply enough pressure to the rails.. Volts at the pump are fine and has new filter and pressure reg and the tank has been cleaned twice.

Any help would be great thanks..

[immortality]

possibly a restriction somewhere between the fuel pumps and the fuel rail. check the fuel pressure at the rail and just after the pump pushing to the fuel rail from the swirl pot

[hako]

Is there any chance the fuel pump is not being cooled by the fuel return line? - I know they overheat/fail if the return pipe is dislodged and fuel doesn't contact the pump body.

[Patrol308]

ill check out the return line one it may be that. but i dont think it would be a restriction anywhere it all new fuel lines but ill have a look at both and see what else others come up with cheers

[immortality]

what fuel pressure you running at the fuel rail? just to make sure i'm reading the OP correct, when you had just the internal fuel pump it failed, you then fitted new internal pump feeding a swirl pot and then a external pump feeding the fuel rail and then the external pump failed but the internal lift pump to the swirl pot is fine?

[Patrol308]

No its running an external pre pump which was off my brothers which was feeding an injected blown 350 swirl pot so it can supply enough fuel to the swirl pot.. its just any high pressure fuel pump that keeps loosing enough supply pressure after 1 - 3 months. The pressure at the rails is around the 340 mark. Cheers

[Patrol308]

it then drops though to about 90 when the pump fails