No Power To Fuel Pump

ok, well the car started fine. i went inside and it had shut off by the time i got outside again. i removed the fuel pressure regulator just incase it had quite working and put a fuel line from the filter to the carb. i noticed the fuel bowl has no fuel in it either. i listened for the fuel pump to come on a few times by turning the key. nothing. i checked the power to the plug that goes into the fuel pump. its not getting any power at all. not even a slight bit. i did check it with a multimeter. this has just happened within about 30 minutes. it was driving fine earlier. maybe the relay or cut off valve?

is there even a relay to the fuel pump power? i really havent gotten into the circuit of the fuel pumps power. would it be a bad idea to run the pump off a switch through a relay. i have one sitting here that i can just wire up real quick. i think i'm gonna do that for now, but i would like to get it figured out.

You can run the pump that way, with a switch.

Just remember to turn it off when you turn off the car... and run the pump a bit before starting the car.

The fuel cut off relay is supposed to be on the fuse box in the car, behind it, plugged into the back I think.

There is a relay up under the dash. It's behind the fuse box though I forget if it's labled. It has a metal cap with round holes on the end of it if that helps. It's actually a rpm switch iirc meant to cut the fuel pump out if you over rev I believe (not that that makes any diference on a carburated car, since the fuel is already in the bowl it just causes you to lean out). You might be able to dig up some better information if you search for "fuel pump relay", I know this has come up before. You can just jumper it with a wire if you want, thats what I did when it didn't like my msd's tach signal. If you plan to leave it jumpered then go to radio shack and get some spade connectors the same size as the relay terminal and crimp them on to some 12ga wire and you should be fine. I know which terminals to jump etc is listed in another post.

[edit] Since a20a1 beat me to the post... You shouldn't need a switch if you jump the relay, the power feed to the fuel pump comes from the ignition switch so the pump will be on when the key is on. I like this better then a seperate switch because you can't forget to turn it off.[/edit]

andy

well what i was going to do is use a relay that i already had wired up for lights. it uses a circuit breaker and a relay inline, then i already have a switch for it. its all wired up, all i need to to is run a wire from the relay back to the fuel pump, and then install a ground wire. sound good? i dont have time to be messing around trying to find the problem today. i'll probley just do it when i'm at school. that'll give me something to do. but yeah, i'd like to be able to drive the 3gee tonight at least. i'll tell y'all how this goes. if anyone has any similar problems they've delt with that might just help.

alright, now i ran power to the pump. i tested to see if it'd ground and the wiring is all good. now as for the the fuel pump working when i hooked it up, i didnt see or hear any signs of it working. so, its possible that when i tested the power wire i mixed up the + and - because i think that makes a difference when i'm using the tester. aside from that, the pump makes no noise what so ever. so i'm gonna take that bitch out and see if i can find anything that would make the motor not run. could be a loose wire to the pump or a clog which i dont think is likely. i should still have the ticket for the pump and it has a lifetime warrenty. so i'm good there. i'm gonna wait till tomorrow to get the pump out and probley exchange it.

https://www.3geez.com/forum/showthread.php?t=45641

oh believe me i've already done this before. its pretty easy getting the pump assembly out, but getting it back in can take some manouvering to get it set in there. must have baffles in it?

oh i did find the receipt, so there's no worry about that anymore. i was also gonna say, does it sound like the fuel pump is just bad? i mean, i wired the pump up and put power to it and nothing happened, not even the sound of it running. i guess i should wait to see if a wire is loose that's connected on top of the pump itself.

yeah there are baffles... you need to face the pump a certain way so the fuel pick up is in the right spot.

well, the reason i was stumped on this was because i had replaced the fuel pump about a year and 2 months ago. so this thing really shouldnt have gone out. anyway, i took the pump out and tested it once again. nothing, no circuit made through it. so i took it up to the store and exchanged it. put the new one it and it works fine. so the thing is, why wasnt i able to read anything on the power plug? maybe because it turns on for a few seconds and the multimeter didnt read much in that time? anyway, i got it fixed.

If the engine isn't running the fuel pump "relay" shuts power off to the pump. IIRC it works kind of like a rpm window switch. Its a pain because if your bowl is empty you have to crank the car to fill it up (real annowying if you let the car sit for long periods and all the fuel evaporates from the bowl). The idea is to save wear and tear on the pump and keep the carb from flooding if you sit with the power on and the pump off.

andy

didnt know that bit. thats some shit though, i'd just power the pump by independently if i have the problem again i guess. i have the wiring there now. so as for the fuel pump. i had it just about exactly a year and 2 months. i havent put much more than 15000 miles on the pump. why the hell would it go out? that was just totally wierd. at least i kept my receipt with the warrenty info. and the fact i'm a regular up at oreilly's is a good thing. seems to work great now. it even started up right away with an empty fuel bowl. the last one didnt fill up the bowl that fast or get fuel up the line as fast as this one seems to. hopefully i dont have to do this again. but atleast its easy as it comes if i need to do it again.