[vector1]

is your iac reading between 5-8?, found at the lower right of target idle speed table?

i don't have the dual sync, but the crank offset is used to adjust ign. timing to coincide with crankshaft position, so spark occurs at correct time. did you force the timing and check for correct reading? depending wether you're using analog or digital spark amplifier there are two wires that can be reversed, on my setup it would be the crank trigger wires, the analog amplifier is correct with retarded timing reading, the digital is correct with advanced, this may not apply to dual sync dist. setup.

the cam sync just tells the efi the rotating assembly is coming up on tdc and to get ready to start the firing/injection sequence again, it is driven off the cam, as in distributor, but has nothing to do with the valve timing events.