Just wondering what the Camshaft Sensor does in my effort to fix an intermitent powerloss/hesitation on an MY94.

I have a spare one to try along with a MAF from a collegues car, but was interested to find out what the Cam sensors does that the Crank Sensor doesn't.

 

On a four stroke the crank turns twice for each set of suck, squeeze, bang, blow on a cylinder. With just the crank sensor the ECU doesn't know whether a cylinder is squeezing or blowing. The cam turns half the speed of the crank so does one rev per cycle, a cam sensor can tell the ECU exactly where the engine is in it's cycle. I guess the crank sensor is going to be much more accurate (as the cam sensor is via a stretchy belt) so you don't just fit a cam sensor on it's own you fit both.

With grouped injection the ECU doesn't need to know so you just need a crank sensor. With sequential injection the ECU needs to know which cylinder is about to fire so you also need a cam sensor.

 

Cheers Mate, that all seems to make sense. Thanks