so I worked all bloody day on this,

took out timing chain (it was sort of loose, replaced it) and made sure the timing is right on. The compression of the first cylinder goes on right before it hits the timing mark on the dampener.

i removed the valve cover and checked the rockers and all, turned engine and when the valves open, the camshaft mark is 100% correct (used some thin allen key i had).

so, its still backfiring but the timing is perfect, and so is the camshaft position in relation to first cylinder.

i am afraid the last thing is the PCM?