I've recently started having a problem with my 89 Firebird. Sometimes when I turn off the car and remove the key, the fuel pump continues to run. It varies how long it continues to run for, but usually around 30 seconds. One time it stayed on until I disconnected the batttery. I already changed the fuel pump relay, but I doubt that is the problem because if you disconnect the relay the fuel pump continues running. I hear the fuel pump click when the fuel pump turns off so can someone explain how the fuel system works, i.e. where does the fuel pump relay get the signal. Any ideas on what can be the problem or any info is appreciated. Thanks.

 

There is an oil pressure operated switch screwed into the block, located just above the oil filter, that is paralleled with the fuel pump relay. Sounds like that is the problem. To verify that it is, remove the plug from the switch.

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Tim

1992 Z28, 305 TPI 5 speed, 12.0 sec @ 114.8 mph

1984 Berlinetta 305 TPI Auto, 13.8 sec @ 99.7 mph