https://www.eriecountyohiohistory.com/west-house/Anyone know exactly how these Ecotecs with VVT know where in the cycle the crank is for the purpose of spark timing? Sure, there’s a crank sensor but does it figure out if it’s on the compression or exhaust stroke? From the cam sensors? Seems like that would take a few milliseconds and delay starting.

 

The camshaft and crankshaft sensors

 

OK, thanks!

 

If you look at the intake camshaft the driver’s side end of it has webs to trigger the camshaft position sensors