Number of rotation sensors.

[einarp]

The Weber Marelli unit uses crankshaft and camwheel sensors.
It does need to phase in before firing. I can't imagine any system that would
fire on the first compression stroke unless using a coded disk or a 
distributor.

It will stop firing if cambelt breaks, because it looses phasing information.

That doesn't help your valves a bit, as many can attest. The damage is already
done.


--
einarp at ade.no  ( Maserati Biturbo Spyder )