Timing issue

[prophecy]

well here goes nothing, i have a sr20det blacktop and there is something throwing off the timing. i've reset my CAS following the frsport guide, still runs rough when its set at the proper timing. i have a timing light and the only position that the car will rough smoothly is the 2nd peg from the right. so im trying to figure out what the problem is, i've checked my coils and my injectors both seem to be working as needed also i've even replaced my coolant temp sensor just for shits and giggles. so was wondering if anyone might know any other causes that would throw off your timing.

[Frank_Jaeger]

How do you know mechanical timing is good?

[prophecy]

i have a timing light and so far from what i have seen online the correct timing would be the 2nd notch from the left.

[Frank_Jaeger]

I'm talking internally. How the engine's pistons and valves are synchronized. If this is off, it could produce results like this. If you bought your SR from someone who tried to rebuild it, they might have messed up.

Where or who did you buy your engine from?