No fuel?

[A5295]

Guys, Ive been hunting a fuel issue on the GF's 86 GT for a bit now, and am left scratching my head...

Before I go into detail, her 86GT has a '93 engine, with MAF and I believe an fms fuel pump (255?) No other mods to the engine, other than underdrive pulleys, and ac/air pump delete. LT BBk Headers, and dumped Flows.

Car has run flawlessly since she got it but about a month ago, as she turned the key on, I heard the pump prime, and then it sounded like it kind of fell off, like weakened and died. Car hasnt started on it's own since.

No prime of the pump, no pressure, no run. Pump can be turned on jumping it from the battery to the orange wire on the pump relay. Car runs just as it always has like that.

So far I've
-Checked fuses - all ok
-swapped relay from my car - no good.
-swapped ECU (known good) - no good.
-Swapped Ign switch - no good
-Pulled the engine harness and checked for breaks, and bare spots - nope here, either.

Guys, I cant figure it out for the life of me, and I'd rather not run her pump to a switch, or rig the wiring to work when she turns the key on by attaching the pump feed wire to an accessory source, with a fuse link and everything.

Any ideas?

Thanks!

[silverstangboy]

wooooh, well Mustang FAQ - Engine Tech, Air Bag, ABS, Brake Home Page will help. I will say this much if you don't use the exact same fuel pump relay (don't trade out for one from a different year, yes it will fit) you will have problems, however I don't believe that is your problem. you will have to test your harness with a digital multimeter via the website linked above. my guess would be that the output to turn on the relay from the computer never makes it to the relay, but i'll let you decide from your own troubleshooting, good luck, your on the right track.



oh yes, your relay is under the driver side seat right? make sure and clean the connection to the main harness inside the driver side kick panel.

[A5295]

there is a relay there, but the one I jumped, that will allow the car to run, is actually right behind the battery, mounted on the driver's side apron...