fuel problem

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Apr 16, 2003 | 10:05 PM

smiley1544

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fuel problem

I have an 89 bronco with 302. The fuel pump turns on and runs but not shut off. turn the key on and it will run continuosly for ever. I replaced the relay and it did not cure the problem. It has pressure, it will shoot out of the schrader valve and hit the ceiling. what could it be.

Apr 16, 2003 | 11:11 PM

RRMike

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Joined: Feb 2003

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From: Roseburg OR.

fuel problem

I don't know anything about your rig but I would think that that relay is hooked to some fuel pressure regulator or sensot that tells it when to turn the pump on or off. Maybe replace that or make sure it's hooked up and working???

Apr 17, 2003 | 08:08 AM

steve83

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From: Memphis, TN

fuel problem

There's no sensor - the computer controls the relay by switching its ground off & on, so diagnose that relay's ground wire for a short to ground. It should run straight to the computer. Check the wiring diagram in the Haynes manual.

Apr 17, 2003 | 08:45 AM

smiley1544

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fuel problem

I just found out today that it didnt want to idle before it quit if that helps for anything.

Apr 17, 2003 | 12:00 PM

ambrose

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fuel problem

there is also a 2nd relay . the EEC relay under the dash and should be near the processor. This energizes the fuel pump relay, so it could stuck as well.

ambrose

Apr 17, 2003 | 01:31 PM

steve83

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From: Memphis, TN

fuel problem

On an '89, the EEC relay is right beside the FP relay in the engine compartment. One's brown & the other is green.

Apr 17, 2003 | 02:59 PM

jeep8589

Mountain Pass

Joined: Sep 2002

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From: covington

fuel problem

I am not quite sure what you are saying about it not shutting off. I am assuming you mean when you turn the ignition to the on position that it runs until the ignition is turned to the off position whether or not the engine is running. Normal operation is when you turn the key to the on position it should run for a couple of seconds, then shut off. When the vehicle starts then it should stay on as long as the engine is running. It should then shut off after the engine quits running. There is a jumper that is shown in the haynes manual that will make the fuel pump stay on so you can test fuel pressure. Make sure that it is not shorted or grounded. I am not sure how the fuel pump on the fords know how to stay running while the engine is on, but I know some cars use a oil pressure switch that turns the fuel pump off when it senses 0 oil pressure and on with positive oil pressure. If ford uses this, which I am not sure, then maybe this sensor is bad.