Runs crapy till 3500 RPM???? why

[Bmxr152]

after RE-aligning my timing belt to the right way, my car started to run perfect for about an hour or so, then it started to backfire and studder and sho like 43 counts of knock at partial throttle and as soon as i hit 3500 RPM it all clears up no, studering or backfiring. Could it be that i have an exhaust leak on the manifold?

 

[chris4g63t]

after RE-aligning my timing belt to the right way, my car started to run perfect for about an hour or so, then it started to backfire and studder and sho like 43 counts of knock at partial throttle and as soon as i hit 3500 RPM it all clears up no, studering or backfiring. Could it be that i have an exhaust leak on the manifold?

No. Check for boost leaks and check your plugs

 

[Bmxr152]

Found out what was wrong. One of my spark plugs was smashed to the tip. It was on the cylinder closest to the timing belt. How could of the happened?