Well I’m done with my build!!!! But I ran into a problem and I need some help. Whenever I hook up my battery the fuel pump starts to run and the key is not in the ignition. Has this every happened to any of you guys? What do you guys think is going on?! On top of all that my car will not even try to turn over. O and a little more info on the fuel pump, I disconnected the computer and the pump continues to run. I was looking in my book today in the wiring diagram section and the thing that I saw that I think could make the pump run is the fuel pump relay but I have no idea were this is do any of you guys know were this is?? Well any input would be greatly appreciated. Thanks you guys.

 

Could be the realy is stuck. Or it could be that the oil pressure switch is stuck. It's easy to unplug the relay to find out.

 

the pump realy is just above the wiper motor on the drivers side of your firewall. When you click te key on you should here it. I think there are two or three relays in that bracket and it "should" be the one closest to the motor(to the right side of the car). It would be odd for it to be stuck on but it's possible. The oil pressure switch shouldn't cause it to stay on even if it's bad looking at the schematic.

 

Looking at the schematic, if the oil pressure switch remains closed, the pump will run until the battery fails:



You can use the diagra to identify the F/P relay by wire color. The relay which has those color wires connected will be the F/P relay.

 

Yes it would and yes it could. They are wired in parallel, the OPSU being a backup to the fuel pump relay. If it should fail, the OPSU will power the pump given there is ~4psi of oil pressure. But that's in a factory setup. He has a build, so it really depends on how he has things wired, I suppose.

 

Thanks for the input you guys!! Well I disconnected the fuel pump relay and the fuel pump continued to run!! Then one by one I disconnected all the relays under the hood and the fuel pump continued to run, finally all the relays were disconnected at the same time and I hooked up the battery and the fuel pump still ran!! I have no idea what to look at next. Any suggestions?! Thanks again for all the input!

 

as stated above , disconnect the oil pressure switch

 

can you guys tell me were the oil pressure switch is located? Thanks again

 

usually right above the oil filter

its screwed into the engine block.. plastic wire connection,

AND YOU NEED A SPECIAL SOCKET to get it off, you wont be able to use normal sockets, vice grips, etc, you need to borrow or buy an Oil Pressure Sensor socket head

-there is also a fuel pump switch! tho

its located usually threaded to an elbow going into the intake manifold, underneath or alongside of the distributer... its got a one wire setup at one end.. not sure how it works, but it somehow acts a a fuel pump switch

Oil press sensor - $ 16
Fuel Pump switch - $34

good luck

 

crap, I dunno what I was thinking. Yea, the oil switch can do that and after I went back and looked at mine I should have said the relay was the the left of the brake booster as well. And there are two relays on that bracket too....... sorry about that

 

The unit on the drivers side of the distributor, with a single wire connection, is an oil press sending unit. It is for the oil press gauge in the dash. As far as I know, it has nothing to do with the fuel pump.

The oil press switch for the fuel pump is located just above the oil filter as prev mentioned. That's what needs to be unplugged to stop the fuel pump.