I can't start my diesel 75. I suspect the cam sensor as if it will start (it does occassionally) it will then run perfectly OK. The cam sensor is only used for starting.
Its not the fuel pumps or the relay, they are all known to be working.
The engine will turn but as the fuel pumps aren't coming on it doesn't start.
I repeat this is not related to fuel pumps!
I measured the cam sensor's resistance and any combination of the pins is infinate. (open circuit)
Is this normal, or what values should I get?
There is a very complex chip in that particular sensor, whose inputs and outputs are high impedance, so any meanigful resistance measurement is not possible.
If you are interested, what goes on in that sensor is almost unbelievable. The actual Hall detector is but a small part of the processing which goes on in there. Because of the profile of the cam, it is not possible just to sense when it has got to a particular position. So there are lots of checks, hence the complexity of the system, which I have reproduced below.
The ABS and crankshaft sensors are a little simpler, but they all have a chip in there, to present the engine ECU with a good signal.
So not only the little magnet in there can get weaker, but the functionality of the processing can be affected by temperature.
Just a thought thought. A little fridge magnet placed on top, may just provide a little more magnetic flux to make it work.