I just had the valves replaced on a cylinder head for a j20a DOHC interference engine.
I'm trying to align the camshaft sprocket to the markings on the cylinder head, but they snap back to where they were once I let go.
It's from .5 to 1 tooth off.
The question is, how many teeth is acceptable before you see valve damage?
In my experience, you get at least one or two teeth out before the engine is physically damaged. However, I would suggest you look into whether or not your engine should be temporarily fitted with a cam locking tool during timing belt replacement.
I'd also strongly advocate turning the engine over by hand prior to attempting to start it so you know for certain that it isn't mechanically locking up internally.
given the word "interference" then I would assume that there is little or no room for error on the timing. Interference for engines tends to mean that the valves occupy the same space as the pistons at different times moving out the way as the other arrives. The springs closing the valves can cause the cam to rotate away from the timing point, so there is usually a hole to lock the position while you fit the chain, you will need to check the manual for the correct procedure.
