As I seem to have started something, I would like to point out that the 4 or 3 pulses is the signal given out of the ECU to the tach, What goes in or how the ECU deals with it I dont know
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So how they come up with the 4 or 3 is a guess other than its an easily calculated number of the amount of tangs/pips on either the crankshaft or camshaft.
The ECU knows where the engine is by the missing tang on the crankshaft, It knows what part of the cycle it is on by the camshaft sensor, from that it can work out where to spark or inject on a count of tangs on the crankshaft.
Thats how I read it anyhow
. Other than that I know nothing
.
Its too early in the morning to be thinking I need to go do some manual labour
.
J
