fuel system not presurizing

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Apr 8, 2002 | 02:59 PM

a851yy07

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From: joyzee shaw

fuel system not presurizing

got a small problem with my 85. When i turn the key to the ON position i can no longer hear the fuel pump build up pressure and it is taking forever to start warm or cold. If it has sat for more that 12 hours i usually have to take a can of starter fluid and give it a few squirts for it to kick over a few times and then it will run fine.

Any suggestions

[Modified by a851yy07, 2:02 PM 4/8/2002]

Apr 8, 2002 | 03:07 PM

XTwinTurbo

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From: Toronto, ON, Canada

Re: fuel system not presurizing (a851yy07)

Check the your fuel pressure when you turn the key to on and also when you start the car. You should see the pressure raise and hold itself for some time.

If the pressure raises (~42psi) and drops then the fuel pump should be good (of course it could be leaking) and you should check the fuel pressure regulator and injectors for leaks.

If the pressure does not raise (0 psi or only a few above) then your fuel pump is most likely dead or you have a bad fuse, relay.

Just a few suggestions.

Apr 8, 2002 | 05:41 PM

65Z01

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From: SE NY

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Re: fuel system not presurizing (a851yy07)

The FP fuse and FP relay are used to power the FP (for about 2sec) during starting and the Oil Pressure sw powers the FP during normal operation, once the engine has started.

Sounds like the fuse or relay is defective. On '85-'87 Corvette the MAF burn-off relay is the same as the FP relay and cost about $13.

Apr 8, 2002 | 05:51 PM

a851yy07

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From: joyzee shaw

Re: fuel system not presurizing (65Z01)

Fuse is fine. Where on the car might i find this relay that you speak of???

:)

[Modified by a851yy07, 4:51 PM 4/8/2002]

Apr 8, 2002 | 06:00 PM

KYVette90

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From: BowlingGreen KY

Re: fuel system not presurizing (a851yy07)

Does a lot of smoke come out when it finally starts? If so I would say a bad regulator or leaky injector. But it sounds like the fuel pump. Does it run ok when it finally starts? Could also be ignition. Don't rule it out.

[Modified by KYVette90, 4:01 PM 4/8/2002]

Apr 8, 2002 | 06:03 PM

a851yy07

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From: joyzee shaw

Re: fuel system not presurizing (KYVette90)

runs fine after it starts up it just takes forever to start if at all without a few shots of starting fluid.

Apr 8, 2002 | 06:20 PM

65Z01

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From: SE NY

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Re: fuel system not presurizing (a851yy07)

I think the FP relay is the outer of the two relays behing and above the battery, but not sure as the diagram is not very clear.

Apr 8, 2002 | 06:53 PM

dizwiz24

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From: NEwhere Ohio

Re: fuel system not presurizing (a851yy07)

Check the fuel pump, strainer, and fuel filter.

I am living proof that the fuel pump is not a 'either it works or doesn't'

I was getting low (38psi) fuel pressure and was having idling, and occasional stumbling problems around 3000 RPM (my opti, wires, and plugs are brand new BTW). Also the fuel pressure was taking a while to build up to 38psi after starting, whereas most cars shoot right up to pressure

I had my fuel pump replaced and now get 45 psi. Runs good