1989 Misfire when put into D
Thread Starter
1st Gear
Joined: Mar 2016
Posts: 1
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1989 Misfire when put into D
New to the forum and just picked up a C4 with 106000 miles, i drive it weekends, although not every week end, it seems to have been running fine until recently, idles in P & N fine, but when put into D it gets a misfire. Any thoughts?
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
When the trans is put into gear the ECM increases the idle to compensate for the extra load. It does this by stepping the IAC out until the desired idle is reached. That indicates a problem with the IAC.
Cleaning the IAC pintle and IAC passages would be a good idea.
Cleaning the IAC pintle and IAC passages would be a good idea.
