I have a 1989 iroc 350 that is causing some havoc with me. I had service enginge soon light on for awhile now but as I never really take the car on long trips I hadnt noticed anything.

But yesterday a drove about 50 or so miles and the light went out and I noticed the car was a bit snappy (more peppy) anyway when I got home the fuel pump wouldnt shut off and contined to run while I was inside at work I came out 7 hours latter and the car was dead.

this happens when ever I make a long trip the fuel pump wont shut off.

I am guessing that my fuel pump isnt working properly untill it gets a good run then thats why the trouble light is on then once running the light goes out but then it doesnt shut off.......

do you guys think that it is the pump going bad?

 

Run your codes from the SES light first. Start thinking about the pump like you said or a relay as well. Codes are the first place to start.

 

See if the pump shuts off when you unplug the oil pressure switch first.

 

Might add that it is the 2 prong connector.

 

I have heard about the Oil Pressure Sending Unit being connected to the battery and fuel pump or something along that nature

 

Definitely not the pump. The problem has to be in something that is supplying the pump it's power. A sticking relay is likely the cause.

 

It's the oil pressure sending unit - it does have a direct connection from the battery and can go bad in such a way that it 'thinks' it's sensing oil pressure when it's not, and thus will run the pump always. Until you get time to get to it, just unplug the fuse for it when not driving to save the battery. The fuse is located in the fenderwell behind the battery in it's own little weatherpack.

I had this happen before myself. New OPSU is about $40.