experiencing misfire on cylinders 1.2,3 have replaced plugs and wires .. runs rough at idle runs and drives. once its over1700rpm it smooths out.

 

Welcome!

We are going to need some more information.

What vehicle are you working on? What engine and transmission does this vehicle have? Two wheel drive or four wheel drive?

Any other information you could give us will help us help you.

Is the "Check Engine" light on?

Did the misfires start out of the blue? How long has this been a problem?