Hi tjburns44. Welcome to the forum. I had to scratch my head a few times. It's possible your mechanic doesn't understand how these circuits work, but I think it's more likely he just isn't good at explaining it. An ignition coil becomes defective on its own. Nothing else will cause it to fail. And magnetic sensors don't lose their magnetism. If you look at your crankshaft position sensor, I believe you will find it has three wires. (I'm doing this from foggy memory). Three wires means there is circuitry inside the sensor that amplifies the pulses generated by a coil of wire wrapped around the magnet. Those types of sensors fail often and can become heat-sensitive. Another version of this is the Hall Effect Switch which replaces the coil of wire with a magnetically-controlled transistor.
Two-wire sensors are also a magnet with wire wrapped around them but they produce a high enough signal that no other circuitry is needed. They connect directly to the ignition module or Engine Computer.
While I suppose it is possible for the magnet in a sensor to lose its magnetism, I suspect what your mechanic meant was it was losing its signal. That WILL cause the engine to stall suddenly. Magnetism won't be lost that fast to cause abrupt stalling.
I had to use '97 service information, but I think the circuitry is the same. You should have a crankshaft position sensor and a camshaft position sensor. Both have three wires, a 5.0 volt power supply for the internal circuitry, a ground wire, and the signal wire. If these sensors are working, the Engine Computer will turn on the automatic shutdown relay anytime the engine is rotating, (cranking or running). When the ASD relay turns on, it sends voltage to the ignition coil, injectors, fuel pump or pump relay, oxygen sensor heaters, and alternator field. The most obvious clue is the fuel pump but it can be hard to hear. Instead, use a test light or cheap digital voltmeter to measure for that voltage on the green wire with black stripe at the ignition coil. If you find battery voltage there during cranking, the sensors are working.
Wednesday, July 21st, 2010 AT 1:51 AM