Camshaft/crankshaft sense

[Tom Cloud]

>> A second question is, does anyone sense crankshaft and camshaft 
>> positioning separately?  This sounds silly, but it would let one sense
>> timing belt/chain failure almost instantly, so one could inhibit plug
>> firing which might save some bent valves.  In theory, you could sense
>> belt/chain wear, but I don't think you'd want to spend the money on
>> that level of precision.
>
>Ford do it this way, ie, a cam sensor for TDC and crank sensor for
>engine position.

Ed .... on my '82 Bronco, there is only a 4-pointed crank
transducer/sensor and there (was) nothing in the distributor.
All that's changed now ;-)  [have now disabled the crank
pickup / confuzer control and gone back to older distributor
with vac advance and driving ignition nodule directly.

question, how did that system work ?   how did they know
where TDC was -- or did it matter ?   Actually, I guess I
can figure that out myself ..... doesn't matter, because
you just give a spark pulse, delayed by a certain amount,
for each crank pulse and just set the rotor to point the
spark at the correct plug.

so, how's this different from what you describe above ?

Tom Cloud <cloud at peaches.ph.utexas.edu>