Rough Idle. on 2002 Chrysler PT Cruiser

Idle is rough and vibrates quite a bit, runs good under acceleration although it does lag a little if you have to get on the gas very hard. Pulled the plugs and they look good, no deposits or anything. Not pulling any codes.

by in Wylie, TX on March 19, 2012
1 answer 3 comments
ANSWER by , March 19, 2012
YOU MAY HAVE A BAD COIL PAK OR POSSIBLE ECM ISSUE I HAVE SEEN BOTH IN THIS MODEL. THE ECM CONTROLS COIL SPARK AND THESE ARE KNOW FOR BOTH PROBLEMS
COMMENT by , March 19, 2012
IDK how old the coilpak and plug wires are. The wires look and feel OK, not cracked brittle or anything, and the coilpak shows some brownish discoloration where wires plug on. Is there an ohm test for the coilpak?
COMMENT by , March 19, 2012
YES BUT VERY IN DEPTH
COMMENT by , March 19, 2012
OK thanks. Just cleaned the TB intake and butterfly. They were pretty carboned up and kind of an oily paste built up. Idle has improved but will have wait till I drive it to see if that cured the acceleration issue.