Shutting off



I have a 1996 Ford F-150 with a 351. The problem is, it shuts off-literally shuts the engine down- when driving down the road. Most of the time it will start back up (at highway speeds) without doing anything. I have replaced almost all of the emissions/electrical stuff on it and still does it. I need this truck to be dependable for the family and it isn’t working with me. I have replaceed the following items: TPS, plugs, wires, cap, rotor, battery, cables, vacuum pump, spark control module…etc. Last thing to look at is the computer. Is my PCM telling my engine to shut off?


I have replaced almost all of the emissions/electrical stuff on it and still does it.

Why did you think it was the pollution stuff?


How about the ignition switch? There is current flowing through it, it has contacts, so a little bit of corrosion or pitted contacts might make/break the electrical connection momentarily.


HOW the engine stalls, is a useful clue. Does it stumble, then, stall? Does it suddenly stall?
If it stumbles and stalls, that points to a fuel control problem. Have you changed the fuel filter? Swap out the fuel pump relay with another lesser used relay.
Do you have anything electrical which loses power at the same time as the stall occurs?


the vacuum pump was bad and it needed replacing. Along with a couple other items.


replaced the coil and the ignition module.


Your car has OBD II, and the codes are none, or the CEL would be on. The PCM may not be able to tell you if it is causing the problem. Sometimes, it’s guesswork.

If you have a distributor and it has an external condenser / capacitor, try removing it and see what happens. It used to work on a 1986 model. You might want to let it hang and tape over it to check it. I’m not familiar with The 96 truck.


Stonecold answered a question (from another responder) with a partial list of parts changed, a day AFTER I asked him to describe (tell the symptoms of) the stalling. If he won’t supply pertinent information, how does he expect to receive advice which might lead to a cure?


First off, i tried to reply and it wouldn’t take. Not my fault. next, the engine shuts off and then fires back up again at highway speeds. At lower speeds it will have to be re-cranked and this sometimes takes up to 15 minutes. I replaced the fuel filter 3 times and both pumps are sound. All i can figure now is the EEC.


“both pumps are sound”

What about the tank selector switch? If it is a simple toggle it will be easy to eliminate as the culprit anyway.