Fuel Pump Run On

raptor · 06-12-2003, 12:51 PM

Hey all, I now have my car dialed in. Its running perfect after messing with the fuel pressure and idle.
Yesterday I shut the car off and I could still hear the fuel pump running for maybe 3-5sec then it shut off. I started the car again and shut it off did the same thing. This morning I went to start it I didn't hear the pump. When I turned the key it took more than the normal few cranks to run. It did start. I'm think fuel pump relay. But dont want to replace it if anyone has other thoughts let me know.
Thanks

jimberg · 06-12-2003, 04:35 PM

Why wouldn't you want to replace it?

raptor · 06-12-2003, 04:42 PM

Well Jim lets see. Maybe replacing good parts with good parts is your bag ain't mine. I'm wanting to know if anyone had this problem before and if it is the fuel pump relay for sure. When I turn the key to on the pump doen't come on. But when I turn the key off the pump comes on. Then the car starts right off. If I just turn the key it takes a few cranks to start. Then when I shut it off the pump runs for 3-5sec. then turns off. Relay?

jimberg · 06-12-2003, 04:55 PM

I thought you already decided that it was the fuel pump relay, didn't want to replace it, and was asking for a way to jury rig it.

Pull the connector from the fuel pump relay and probe the pins that activate the relay with a voltmeter. See if the signal to activate the fuel pump relay comes in when you turn the ignition to the on position. Turn the key to the off position and make sure that no signal goes to the relay. If everything works as you would expect, then it's probably the relay or the fuel pump. If not, you may have a problem with the computer.

My computer went bad last year and it would activate the fuel pump when I turned the key to the on position and leave it running. You could have a similar problem.

aar0s · 06-13-2003, 12:33 AM

just wondering where the fuel pump relay is at?

PKRWUD · 06-13-2003, 12:55 AM

For you guys, it's under the drivers seat.

Jim's advice is the best you're going to get. There is no "for sure" answer with the limited info you've provided. It could be a few things, but the easiest method to start your diagnosis is doing exactly what Jim suggested.

Take care,
~Chris

06-12-2003, 12:51 PM	#1
raptor Registered Member Join Date: Sep 1999 Location: Dundalk, Ont, Canada Posts: 129	Fuel Pump Run On Hey all, I now have my car dialed in. Its running perfect after messing with the fuel pressure and idle. Yesterday I shut the car off and I could still hear the fuel pump running for maybe 3-5sec then it shut off. I started the car again and shut it off did the same thing. This morning I went to start it I didn't hear the pump. When I turned the key it took more than the normal few cranks to run. It did start. I'm think fuel pump relay. But dont want to replace it if anyone has other thoughts let me know. Thanks __________________ 88GT, 331Stroker,FMS 70mm TB,77mm Pro-M mass air,Ram Air,K&N,GT40/Exployer Intakes,Gasket Matched,FMS 24lb injectors,Crane hi-6 ignition system,B303 cam,Crane 1.6RR,FMS underdrive pullies,351W/heads,port/polish,FMS h/f oil pump,Hedman headers,2 1/2in H pipe Flow Masters,190lph Holley fuel pump,Center Force dual friction,FMS 3.55,Hurst short throw/ trigger T handle,Subframe connectors,Welded torque boxes.

06-12-2003, 04:35 PM	#2
jimberg Registered Member Join Date: Oct 1998 Location: Rogers, MN Posts: 2,089	Why wouldn't you want to replace it? __________________ 351W 89 Mustang GT Convertible

06-12-2003, 04:42 PM	#3
raptor Registered Member Join Date: Sep 1999 Location: Dundalk, Ont, Canada Posts: 129	Well Jim lets see. Maybe replacing good parts with good parts is your bag ain't mine. I'm wanting to know if anyone had this problem before and if it is the fuel pump relay for sure. When I turn the key to on the pump doen't come on. But when I turn the key off the pump comes on. Then the car starts right off. If I just turn the key it takes a few cranks to start. Then when I shut it off the pump runs for 3-5sec. then turns off. Relay? __________________ 88GT, 331Stroker,FMS 70mm TB,77mm Pro-M mass air,Ram Air,K&N,GT40/Exployer Intakes,Gasket Matched,FMS 24lb injectors,Crane hi-6 ignition system,B303 cam,Crane 1.6RR,FMS underdrive pullies,351W/heads,port/polish,FMS h/f oil pump,Hedman headers,2 1/2in H pipe Flow Masters,190lph Holley fuel pump,Center Force dual friction,FMS 3.55,Hurst short throw/ trigger T handle,Subframe connectors,Welded torque boxes.

06-12-2003, 04:55 PM	#4
jimberg Registered Member Join Date: Oct 1998 Location: Rogers, MN Posts: 2,089	I thought you already decided that it was the fuel pump relay, didn't want to replace it, and was asking for a way to jury rig it. Pull the connector from the fuel pump relay and probe the pins that activate the relay with a voltmeter. See if the signal to activate the fuel pump relay comes in when you turn the ignition to the on position. Turn the key to the off position and make sure that no signal goes to the relay. If everything works as you would expect, then it's probably the relay or the fuel pump. If not, you may have a problem with the computer. My computer went bad last year and it would activate the fuel pump when I turned the key to the on position and leave it running. You could have a similar problem. __________________ 351W 89 Mustang GT Convertible

06-13-2003, 12:33 AM	#5
aar0s Registered Member Join Date: Nov 1998 Location: southern Illinois Posts: 312	just wondering where the fuel pump relay is at? __________________ 88 gt convertable =-= cobra intake, accufab 65 mm tb headers alum underdrives steeda alum.lca's, springs, c/c plates kyb struts 230 hp to da wheels http://www.cybersteed.freeservers.com

06-13-2003, 12:55 AM	#6
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	For you guys, it's under the drivers seat. Jim's advice is the best you're going to get. There is no "for sure" answer with the limited info you've provided. It could be a few things, but the easiest method to start your diagnosis is doing exactly what Jim suggested. Take care, ~Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

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