42,000 miles and has a rough idle it`s been sitting in a garage for 6 months. on 1992 Chevrolet G Series Van (G20)

it knocks on take off and smoothes out some on hte road but still knocks some

by in Piqua, OH on October 14, 2012
1 answer
ANSWER by , October 14, 2012
did you change all the fluids??? spark plugs?? fuel filter??? is the check engine light on?? Roy