Incorrectly installed pulley??

[0range_240]

I noticed after I installed my pulley that my car, it started running quite poor, with a rough idle and a slight knocking noise between 2500-4000 rpm, is it possible that I installed my pulley incorrectly?

[180fan]

You running an underdrive pulley? It's possible that the thing wasn't balanced properly. Only other thing I can think of is that your timing might be off?

[0range_240]

how are you supposed to balance it? or is it supposed to be balanced when you get it?

there are three threaded holes for small bolts to go in, what are they for?

Also, I thought of timing too.. any idea how it could have changed my timing though?

[180fan]

They're supposed to be balanced when you get it. I'm not too sure of the three bolts, I think that's for the removal of the pulley. Do you have a pic and the brand of the pulley?