rejeep Posted November 14, 2012 Posted November 14, 2012 S I've been DD my MJ for a few days now since my wife's truck is in the body shop and I've noticed a few things that aren't 100 percent right.. The truck seems to hunt for idle at times and doesn't idle smooth... I can see the hood vibrating a bit... Also after crusing and shifting into neutral to brake the idle will drop real low almost to a stall.. It's a 86 2.5l manual trans. Recent tune up and fresh fuel... Any thoughts where to start..
shelbyluvv Posted November 14, 2012 Posted November 14, 2012 Two things come to mind, Bad IAC or MAP sensor.
Comanche County Posted November 14, 2012 Posted November 14, 2012 :agree: Check for vacuum leaks also going to the map.
rejeep Posted November 14, 2012 Author Posted November 14, 2012 ok.. IAC... I searched the forum and some other sites (RockAuto) and I could not find a listing for the IAC where exactly is this located on the 2.5L engine.. I hate to ask such a noob question, but i really know very little about these early 86-90 FI systems...
rejeep Posted November 14, 2012 Author Posted November 14, 2012 After a little more searching online I found so,etching listed under a 86 cherokee 2.5.... SMP SA4... Hd it in stock and will hopefully swap out tonight
Comanche County Posted November 14, 2012 Posted November 14, 2012 Try cleaning it with some carb cleaner before you replace it. They get some carbon build up on them that can easily be cleaned off.
cruiser54 Posted November 14, 2012 Posted November 14, 2012 First place to look is that group of vacuum hoses near the throttle body. They're usually split. Also make sure all your intake/exhaust manifold bolt are present and accounted for and tight.
rejeep Posted November 15, 2012 Author Posted November 15, 2012 swapped the IAC... might be better.. need to adjust the plunger and put some more miles on it to find out...
cz777 Posted November 20, 2012 Posted November 20, 2012 joking ....most jeep are like women don't like the cold ....iac setting is about 12mm from black base to tip
cruiser54 Posted November 20, 2012 Posted November 20, 2012 swapped the IAC... might be better.. need to adjust the plunger and put some more miles on it to find out... Spray some throttle body cleaner around the intake and throttle body hoses. There was even a TSB for the hoses. And on a 2.5, it's an ISC motor meaning Idle Speed Control. Works completely different from an IAC which is an Idle Air Controller. An ISC controls linkage/butterfly while an IAC controls an air passage inside a throttle body.
cruiser54 Posted November 20, 2012 Posted November 20, 2012 http://comancheclub.com/topic/36058-86-rough-idle-fix-25/
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