Ok, I have a walbro inline pump. Last week I noticed that it was not turning on anymore when i turned the key to the on pos. Figured motor in pump burnt out, i bought a new pump.

I checked the power and ground wires going to the pump with a test light and i had power going to both somehow. put it all back together(with new pump), still nothing. i am thinking relay, My friend that was helping me had a bunch of various relays and found one that looked the same, did nothing, weird thing was that when he touched the test light to the one of the points on the relay(while it was all hooked up) the motor on the fuel pump came on. The harness has been all hacked up and was pretty much a mess, but i have got it sorted out.

So now I figure hmmm, lets ground the pump, run a wire direct to the battery through a switch, and for now i can turn it on and off manually. Well not so good either, we hook it up and i still cant figure out why but, when hooKed up directly to a ground, and directly to the battery, with key off pump turns on and off, with key on no pwer at all. Anyone have any ideas on any of this?


Much Thanks

 

bumpbumpbump Please help, I can not get the pump to come on with ignition, and i cant figure out why the negative wire has power. Thanks

 

Do you mean the "in tank" Walbro replacement?

If you say you get both power and ground (for the first 3 seconds after key "ON") at the wires above the tank, then it should be working... the stock FP relay is just left of you feet in the kick panel.

You could bypass it and run straight to the battery with a "ign" trigger to your relay but make sure you don't burn out your new FP by listening to the radio with the IGN on. You have to find a IGN source that still provides a + while CRANKING.

 

Ok, it is not in tank pump, it is external inline pump. Somehow i have power going to power wire and ground wire. It looked really strange, the ground wire is run to the positive terminal of the battery, but it splits off and continues to a relay, near fuse box under hood by battery..


I thought at first that the relay was bad, i swapped it and had the same problem. I used to hear the pump build pressure when i turned the key on, now i dont. So basically I think my problem lies in the fact that I am getting power to the Fuel pump ground wire. Unfortunally the person i bought the car from did not do the work himself and his mechanic is on vacation. I am kind of doing this blindly.

If anyone knows how and why I am getting power to the ground wire please enlighten me. I have gone through just about every scenario in my head and cant figure it out.

Maybe ground wire is given power to turn pump off when its not in use?
That still doesnt explain why on ignition pump wont start.

If anyone has a Haynes book and doesnt mind checking it out for me I would be much appreciative.

 

It sounds like you're not too comfortable working with electrical circuits... Your 1st paragraph doesn't make much sense to me. It makes it sound like you "shorted" some of the wires.

You may want to have someone do this work for you... You may do more harm than good otherwise...

 

Here's a website... it may help if you are still adamant about working on it:

http://www.classictruckshop.com/club...osch/relay.htm

 

Yeh its not that im uncomfortable, It actually is set up the exact way it was when it worked. The pump just stopped working on me the other day. I figured it was shot. I took a test light to it to see if it had power and it did, ON BOTH SIDES! kinda weird, i got a new pump, put it in figuring the old one was shorted and thats why i had power to the ground. When i disconnected the wires and tested them off the pump I had same result.


I just checked all the wires from the batt. to the relay, to the vacum switch, all look ok. I then hooked the pump directly to batt. and a ground and it came on. I am thinking either the vacuum switch is bad, or the second relay is bad, but i have no clue how to test them.