5.0L (1979-1995) MustangTechnical discussions on 5.0 Liter Mustangs within. This does not include the 5.0 from the 2011 Mustang GT. That information is in the 2005-1011 section.
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I have a 90 LX 5.0 and when I crank it it shuts off after a little while. I think it may be fuel pump related. I have a relay under the driver's seat that I was told was a fuel pump relay. Replaced it. It still chatters when the car is about to shut off. I was troubleshooting under the hood, and another relay on the passenger wall was chattering also. Is this another fuel pump relay? I have not replaced it yet because I don't know if it will solve my problem or what relay it actually is. Should I just replace the pump itself? Has anyone had this problem with their Mustang? Help.....
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When I first noticed the problem the fuel pump stayed on even after I switched the car off. I had to disconnect the battery to shut it off. Now it doesn't do that anymore. Now after I crank it runs about three to five minutes. It start to make a weird noise under the hood, and the relay under the driver seat chatters and the one under the hood on the passenger side.
just start running the diagnostic checks listed there, it gives you a good idea of where everything is thats important for the fuel system. Also see if you can't borrow a fuel pressure tester to see what your fuel pressure is doing as it shuts off.
"Insert whitty comment here"
1988 GT, daily driver with 42k original miles and counting
1983 Chevrolet SS el Camino, lsx swap
88 GT sold, 93GT sold, 93 lx coupe sold
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