forgive me if i posted this in the wrong forum i have a 1997 maxima se i have no spark in cylinders 1,2 and 3 cylinders 4,5 and 6 are fine and have spark i tested the spark with a in-line spark tester, i swithed the coils around to the good cylinders to check them and there all good i have changed the knock sensor because i had a code for that but no improvment i also changed the ecu and also no improvement the car starts but runs like crap no power when you step on gas and it shutters and shakes because its only running on three cylinders any ideas as what to check next thanks

 

Timing might be off

 

Definitely off.

 

what would cause the timing to be off and how do i check to see if the timings off