IZ-Boss

I have a 1984 that I love but I have an issue right now, I have changed the battery cause I thought it might not be good. Come to find out I here my fuel pump running when the car is off. What do I check firstHelp Help?????

ccrazor

Unplug the fuel pump relay..

joe paco

Yep. agree, the FP relay has power, from the computer. a quick shutoff is to pull the fuse. not sure how the '84 works, but 91 is controled by ecm, so if relay stuck closed, it would have no current from ecm when key is off.

joe

AGENT 86

Test the oil pressure switch, it may be stuck closed.

IZ-Boss

Thank you so much !!!!!!

IZ-Boss

ccrazor

If unplugging the relay shut the pump off, the relay terminals should be marked A,B,C,D, & E. IF you have a multi-meter check resistance between A and E, if you get 0 ohms or low resistance you need a new relay. If you get infinity check for voltage between C & B on the connector, this is the power signal from the ECM to operate the relay..

IZ-Boss

[QUOTE=ccrazor;1581097400]If unplugging the relay shut the pump off, the relay terminals should be marked A,B,C,D, & E. IF you have a multi-meter check resistance between A and E, if you get 0 ohms or low resistance you need a new relay. If you get infinity check for voltage between C & B on the connector, this is the power signal from the ECM to operate the relay..

IZ-Boss

YOUR AWESOME!!! thank you Im learning so many different things about this car

ccrazor

Two things that you should look at getting is #1 an FSM (factory service manual) and an electrical troubleshooting shop manual supplement. The FSM covers most if not all problems you will have.. The electrical supplement gives you more detailed schematics of the electrical systems..

IZ-Boss

[QUOTE=IZ-Boss;1581098148]Ok my relay is out but the pump is still running does this mean my fuel pump is bad??? thanks in advance IZ-boss

IZ-Boss

[QUOTE=IZ-Boss;1581099697]Also my relay is 12345 not abcde is that the same as a would be 1 and so on

joe paco

is it possible you pulled the wrong relay? 91 relay is marked as the man said A-E. there is a bank of 5, easy to get the wrong one unless it was vibtrating, or hot. it is not the pump. pull the fuse to shut it off while you work or it will be bad.

** as agent 86 said, oil pressure switch could be stuck closed, and it is always hot, direct from battery, on 91. never sure about other years. fuse will kill current to FP.

ccrazor

If you unplugged the right relay, then you must have a stuck oil pressure switch as Agent 86 suggested. It does not normally operate until the engine has cranked over to build up oil pressure..