fuel pump failure

[d.cassidy]

Hi guys

 

Just replaced old fuel pump. Ran mint. Cut out yesturday and wouldnt fire up again. Ran few test, turned key on/off to hear for pump, not hummin. Checked wiring, no corrosion or breakages bit dirty but good. Changed fuses and it fired up. Drove abit and it @!*% itself again and started up? Any help??

[Nefarious]

check the wiring to the fuel pump carefully. it is known to wear and deteriorate over the years. continuity test is your friend.

[d.cassidy]

Cheers. Im no expert at the electrical/wiring sides of things. Wiring looks good to me. Say I was to get some one to look at it, who would you recommend?

[Nefarious]

If you want to tackle it yourself, you could pick up an inexpensive multimeter and continuity test the wires. If i'm not mistaken, it is fairly common on older trucks for the wiring to break between the fuel pump and the fuel pump relay. If you put one end of your test lead to the fuel pump relay terminal and the other test lead to the fuel pump connector terminal (+ positive terminal) then you should either read 0.1-0.5 Ohm (on resistance mode) or you will get a beep sound indicating continuity (depends on your meters functions).

Also check the ground of the pump as well, if you put one test lead to the (- negative terminal) and one test lead to a clean exposed piece of metal in the vehicle (the whole vehicle is ground) then you should also have continuity or a low ohm reading.

 

The fuel pump wiring is quite simple and the circuit diagram is listed in the factory service manual on this site in the garage section. You may just have to replace the piece of wire going from the fuel pump relay to the fuel pump itself, or the ground wire.

 

If you want to take it in, any auto electric capable place can tackle it. But it would save a lot to do it yourself! Factory service manual is in the garage section.