I just replaced my CA18DET. It starts but the idle varies and then the engine dies, with some backfires, so I'm assuming it's a timing issue.
The engine came with the CAS removed. I had to replace a seized water pump and this involved removing the crank pulley - I also turned the engine over several times by hand. I did loosen a cam belt positioner, but did not remove it, so this can't be a problem. With no CAS on the engine while I was turning it, would this have put the timing out?
The half moons were still on the cam and CAS.

Take the timing cover off and actually check to see it the belt is in line with timing marks.

My mate done the same thing as you and the timing was out by 4 teeth

doing the cam timing on a ca is probably the easiest thing in the world. they have marks on each pulley that line up with marks on the engine, then just for an added benefit they have marks on the belt that line up with the marks on the pullys too

if the CAS is in about the middle of its adjustment then it cant be that far out that it would cause issues