Actually its not a sensor, but a transducer that converts a time varying magnetic field (difficult to measure) into a time varying voltage (easier to measure). Sorry about the confusion that I may have caused. Its certainly not a "generator", don't let that mechanic get away with trying to play engineer.
They're called Hall generators because they generate the timing pulses by using the Hall effect. Nothing improper about that.
Okay, then perhaps its the terminology is akin to a function generator, a box that creates sine waves, square waves, pulse trains, etc. I just have never considered it this way. Whatever, I'm just glad to have been able to help out the original poster get his VW back on the road!
Stop that, you makin my brain work again(lol)!
"To add to that... it tells the computer where #1 cylinder TDC is. Once the engine knows that it will fire the injectors "timed" to the cylinder firing order. If the signal isn't there then it just fires all the injectors at 50% fuel twice per crank rotation. The engine will start and run, but just be down on power some. For all you 2.0l owners just unplug it and see if the engine starts and runs. Be warned the MIL will come on but will go back out in a few days once plugged back in.
Class over-- Beer time!
Hall generators, not sure if Bosch invented or refined it or not but they produce a square wave output directly from the Hall generator. The Hall has
3 wires, power(12v), ground, and signal output. On VW's the shutter wheel inside only has one opening to locate TDC of #1 cylinder.
Its good to see that so many of you guys/gals out there are willing to help out people like myself. The mechanic I went to is very well known and came highly suggested by some 'honda' mechanic friends of mine. The sensor/tranducer/generator can be changed WITHOUT having to change the entire distributor. This should be a really good string for someone out there that has the same type issues.
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