HELP - Can't start engine! Code 13.

[gl1674]

My engine just died some 38 miles from home. :-( And it would not do anything trivial on me.

The last time it started was in the morning - it run unevenly (with misses) for a few seconds with RPMs sitting at unusually low 1000, a few seconds later RPMs hit 2000 and then it was running smoothly. It has never done that before. It run the 38 miles without any problems.

Three hours later it refused to start (engine was still warm!).
Here are the facts:
1. Engine cranks, does not fire at all.

2. Exhaust does not smell gasoline after cranking (obviously ECU keeps injectors shut)

3. Fuel is there, fuel pump does pumping and produces the necessary pressure.

4. ECU produces code 13 - camshaft position sensor after ~3 seconds of cranking. This is the only code I get.

5. Camshaft sensor itself checks out OK - not shorted, not open, 2.5k ohm,
produces voltage if I move metal around it. It is the same part number as crankshaft sensor 2, so I swapped them around, but the ECU code stayed the same, it did not move with the sensor.

6. Timing belt is in place, camshaft sprocket looks OK, does not wobble.
Camshaft does turn when engine is cranked. Crank pulley is in place and the bolt is tight.

7. Wiring from the camshaft sensor to ECU seems to be OK - no shorts to the ground, some high resistance (80 k ohms), seem to be reaching the ECU.

8. Last couple of months it's been having a quite loud noise first couple of seconds/minutes after a cold start that I dismissed as lifter noise - it temporarily went away for 500 miles after oil change & flush and always goes away during warmup. But when it's there it was quite discomforting loud banging... There are no unusual noises during cranking...


It looks like I'm running out of options of what could be wrong. So far my theories are:

1. Both my cam and crank sensors are too weak for camshaft position, but OK for crank pickup.

2. ECU is bad .

3. Camshaft has developed too much endplay and shifted too far from the sensor (there is about 1/10 of an inch clearance between the sensor and the sprocket).

4. crankshaft sprocket is spinning on the crankshaft due to a sheared pin - unlikely, as I saw timing belt moving


Any suggestions - should I do a leap of faith and spend $$$ for a new cam sensor? Or shoot for a replacement ECU first (this is a cheaper option)?

Just don't undersand how the sensors could gradually go bad - do magnets gradually losing their magnetism when warm or what???