1998 Jeep Grand Cherokee Fuel pump

1998 JEEP GRAND CHEROKEE
4.0L • 6 CYL • 4WD • AUTOMATIC
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LDEANA
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  • 1 POST
I just replaced the old fuel pump with a whole brand new unit, and I also replaced the fuel pump relay. I am 100% certain everything is connected as it should be. So, when I turn the key to start the vehicle, I do not hear the pump "hum" or "buzz". The engine turns but it will not start. Any clue as to the problem would be appreciated.
Apr 6, 2014 at 2:42 PM
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CARADIODOC
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The pump should only run for one second after turning on the ignition switch. If you're listening later than that, it won't be running. If you don't hear it for that one second, feel the relay to see if it clicks when a helper turns the ignition switch on. If it does, check for a blown fuse. If it doesn't click, the Engine Computer isn't turning the relay on, and again, check the fuses. Also check for spark. Don't get hung up on the first thing you find missing. If you're missing both fuel and spark, we have to look at what both systems have in common.
Apr 7, 2014 at 4:57 PM