Slow, fast, or rough? Rough (usually rich with a gassy smell from the exhaust) is a bad ecu temp sensor, mostly. Could also be a bad adjustment on the throttle position sensor. Slow or fast, usually slow, is a bad idle control unit, under/behind the TB. This assumes new plugs and good wires. NGK's are the best plugs, and nearly the best wires in my book.

Not responsible for advice not taken...