Evoballs

Fuel pump won't shut off. Pulled F/P relay still runs. Any ideas. Thanks

dawson1112

Yea some how its getting 12v all the time. Does it run with the key on and off?

Is this something that just started occurring?

Evoballs

Won't start. F/p runs with koeo and cranking. fuel pressure builds up and hissing sound at injector. If I pull EEC relay pump shut off. Ran fine car sat for bout week.

Evoballs

I found the relay that was running fuel pump, it was under drivers seat. All the wire diagrams I've found have only two relays. I got 3 one at EEC pass kick panel, one under seat and one in engine compartment pass side. If I pull relay under seat pump shuts off. I've traced all wires all good. All relays are good. What shuts pump off when fuel pressure builds up. Is it timed or a pressure sensor that tells EEC to shut pump off. I'm at a loss because I can't find wire diagram that matches. It's a 02/89 mustang 5.0 conv. I've looked for two days for diag.

mjr46

if eec doesn't see a pip signal with in 2 sec of koeo, ecm removes ground to FP relay coil side.......you could have a bad tfi or stator in the dizzy which is where PIP is generated...meaning signal is being sent from dizzy when it shouldn't be to ecm......like possible bad distributor bushing causing reluctor wheel to interfere with stator.....pulling distributor and checking integrity of shaft bushing can verify such.

aode08

remove the tfi module from the distributor,autozone has a ford distributor tool for that for like 6 bucks, then have them test the unit,get back with us after that because this situation can get complicated.

aode08

http://www.veryuseful.com/mustang/te...ng_Diagram.gif

Evoballs

Thanks. Going to have TFI module tested. And go from there.