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-   -   Engine runs very rough in morning. (http://www.wranglerforum.com/f210/engine-runs-very-rough-in-morning-56623.html)

TheDudeAbides 07-29-2010 12:51 PM

Engine runs very rough in morning.
 
Hey guys, I've had this problem for a month or two now. After leaving my jeep parked overnight or for an extended period of time 8 hours or so, after starting it up it runs very rough for about 2 minutes and then it smooths out and runs fine. I've replaced my upstream o2 sensor and cleaned my IAC and that didn't help it. Anyways I uploaded a video to youtube where you can actually hear my problem. YouTube - Rough start jeep please take the time to watch just the first 30 seconds to hear my problem and let me know what you think it could be. I have a 1997 Jeep wrangler TJ with an automatic transmission. Any help is greatly appreciated.

Indy 07-29-2010 05:00 PM

When was the last time you did a tune up?

flatline 07-29-2010 05:32 PM

x2 on the tune up. sounds like it's missing. or, does it smell like it's running rich?

rrich 07-29-2010 08:41 PM

The O2 sensors really don't do anything the first 2 minutes -= it's still in open loop.
Rough before it goes into closed loop is most often a vacuum leak somewhere. Once it's in closed loop it compensates for the leak.

Check all vacuum lines, check the manifold gaskets. Spray around a burnable carb cleaner to find the leak. Or use propane.

StinkyMud 07-30-2010 05:46 AM

Quote:

Originally Posted by rrich (Post 705979)
The O2 sensors really don't do anything the first 2 minutes -= it's still in open loop.
Rough before it goes into closed loop is most often a vacuum leak somewhere. Once it's in closed loop it compensates for the leak.

Check all vacuum lines, check the manifold gaskets. Spray around a burnable carb cleaner to find the leak. Or use propane.

X2, well said.


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