I'll try to make this brief. The problem is that this "problem" is so inconsitant.... Turn the key to "on" and instead of the fuel pump running for about a second it just keeps on priming. This is an on again/off again problem, but it happens about 50 percent of the time.the other half it either starts or the pump doesnt kick on at all. I replaced the fuel pump relay but it still does it.Any suggestions?93 LXSSP.

 

HMMM!!! It SOUNDS like the relay right off the bat.
1st- double check to make sure you changed the correct relay.
2nd- check for breaks in the wiring harness at the pump( it may be grounding spratically somewhere)
3rd -it MAY have something to do with your ignition switch
4th- check that before you start the car that there is actually pressure on the fuel lines. It is possible that you have a fuel leak causing the pump to prime longer than normal to refill the lines.

It is really hard to say with out checking the car thoroughly. It may be the fuel pump itself. meaning that it keeps priming because it cant build pressure. Does the car stumble when it runs und loads??
Anyway start with that and hopefully the issue will jump out at you and you can find it.

 

sounds like the relay is sticking to me. if that is not it maybe the pickup in the distributor has gone wild and it is telling the ECM that the motor is running. a leak will not make the pump keep running. the motor has to be running for the pump to keep running or it will stop after a few sec.just like when you first hit the key. it is a safety feature. next time you have you dist. out leave the key on and turn the dist. you will hear the pump run and the ignition spark.pressure has nothing to do with when the pump starts or stops on the Fox body's.