Engine stalls at 30mph upon hitting accellerator, then coasts to a stop. then won't restart. starter works, engine turns over, but won't fire up. next morning car starts fine. next week engine stalls again at mph. so far, replaced throttle-bottle, spark-plugs, did stress test on coils turned out negative. 2 ford dealers and 1 mechanic shop so far cannot get it to recur. no codes. all baffled.

Hello first of all


well i am sorry a mechanic cant figure this out its really sad. ok so your problem is your either one of two things but most likely the first one i list.

1. camshaft postion sensor
2. crankshaft postion sensor

Now that being said it most likely the camshaft sensor the reason i say that is when a crankshaft postion sensor is bad the car has very hard starts and most of the time no start issues. When a camshaft postion sensor is bad the car cuts off whil driving and can be hard to start up again.

So that being said they are both pretty cheap parts i would go ahead and replace them both and i would bet my 5 years as ford mechanic that solves your issue.

The crank postion sensor is located behind the harmonic balancer pully or right beside it here is a picture from autozone.com and description.

The crankshaft position sensor identifies position of the crankshaft to the ignition control module (ICM), engine control module (ECM) or powertrain control module (PCM).

Does the car only fail once it has reached running temperature? If so it could be the crank position sensor (CKP). As these sensors get older and begin to fail they become heat sensitive> They work fine when cold but as they expand due to heat they begin to drop voltage below threshold so that the ECU can no longer gets an accurate signal. The fall off in signal can be gradual and evades the OBD. The only other thing I can think off is the ignition module. Often this was mounted onto the side of the distributor but Ford soon realized that these were failing after prolonged exposure to heat and so were then sited on the inner fender. Worth checking. Thermally induced failures are difficult to diagnose but my advice would be to check everything with a voltmeter when cold at start up and then check everything again when hot after the car has died (ignition on position 2), this should help trap the fault. Of the two I would give odds its the CKP.