1- Hey Be very very carefull first of all check ur timming belt by mechanic it may be possible that ur car timings is not right (It can cause heavy demage to engine)
2-May be current problem (spark plugs like that)
3-if the timing belt is right then only other issue may be ur race adjustment.
But the things u mentioned are very close to first problem or second problem.
I am again warning if its first one donot drive the car before it is checked by any mechanic as it may cause serious damage to engine