crazyshuffle

I have a 65 mustang fastback 289,with C4 transmission. When I park it and turn the key to the off position, the motor still runs. It cuts the electical fuel pump off,so after the motor runs a few minutes it stops. This happens about 1 out of every 10 times I drive it,but seems like its happening more often.
I took it to local machanic and had the ignition switch replaced a year ago and took it back about a month ago and he checked the wires and said everything looked good.
It has a HEI blue distributor also. Please help, this is aggrevating.

bop11

How does it cut the fuel pump off? Do you have a pump safety switch that may have a short in it since it probably is connected to the distributor. The HEI has a power lead. Where is this connected? If it is going bad, it might be pulling power from the battery and supplying the coil. Next time after it runs out of fuel or while running out of fuel, check the high side of the coil with a volt meter. Grounding the high side with the switch off should stop the motor and not cause a spark or fuse to blow. If yo get a spark either the HEI is bad, the fuel pump interrupter is bad, the switch is bad or you have a wiring problem.

barnett468

sounds like your ignition switch., looking at wires does not determine if the internal connectors in the switch are good or not. your last one that went bad most likely looked just fine from the outside too.

crazyshuffle

Fuel pump only cuts off when the key is turned to the off position. I got a new ignition switch less than a year ago, and I still have the problem.Also,my mechanic checked the ignition wires and said they looked good and of course when I took the car to him it cut off like its suppose to when he tried it a bunch. THen when I got it back it messed up with me the same day. Car had the HEI when I got it so not sure about how it was installed, but I don't want to go changing stuff myself.