Cold, rough idle -
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Unread 11-14-2011, 02:26 PM   #1
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2013 JK Wrangler 
Join Date: Dec 2005
Location: Pleasantville, NY
Posts: 191
Cold, rough idle

A problem just cropped up... Lately, and I mean since the end of summer, I noticed that it's a little hard to start. Doesn't sound like the battery or starter is on death's door, but takes a few extra seconds to start. Within the past couple of months, it sounds as if the battery is on its last leg to start but does start up.

The battery is several years old so I figured that it's time to be replaced anyway. Before I replaced the battery (a couple of days leading up to it), I noticed that when I started it up on cold mornings, it was idling rough. Revving to 1k RPMs and it sounds like it's wanting to hesitate. It's a little hard to tell because the bottom part of my cat rusted off and it stuck between the cat and the skid plate so it causes it to rattle.

Replaced the battery and it starts the same way (that hasn't changed, still takes a few extra seconds, beyond my previous "normal" to start) and doesn't idle well (sounds rough), vibrates a little, but only when it's cold. After it's up to normal temp, starting it up still sounds the same but it idles fine.

Computer isn't showing any codes so I'm a little confused. Maybe the starter is going out, but would that cause it to idle rough when cold?

OlllllO 2013 Wrangler Sahara Unlimited
[]lllll[] 1991 Wrangler Renegade, 4.0L Auto (Retired 2013)
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