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Tracking misfire 06 Rubicon

Robert Alford

New Member
Mar 29, 2018
Beaumont, TX, USA
Ok gentlemen, Iam back chasing a new issue. This one may stump as I have taken most actions possible, and couldn't find a similar post. If i break any forum rules let me know and it will be fixed.
06 Jeep Wrangler Rubicon with a brand new engine.

Random misfire usually between cylinder 2 and 3. I know this because the spark plugs will quickly (30 minutes) foul out. I can attach a video, but when testing the coil pack I noticed that randomly, and I do mean randomly some sparks won't fire at the appropriate time (this is where I think the issue lies). Have noticed the pipes will turn cherry red within 30 minutes, but the thermostat remains normal.

Actions Taken:
First the coil pack is a year old, will pass Ohm test (bought these items chasing a previous issue)
The OPDA is a year old
CPS is a year old
New Injectors, and can hear them firing
Cleaned IAC (was very nice)
Timing is spot on

Jerry Bransford

TJ Guru
Supporting Member
Nov 9, 2015
Escondido California
Exactly what brand and model # spark plugs are installed? If they are platinums, are they single or double-tipped? As in is the platinum coating on just one or both sides of the gap? Single-tipped platinums will cause misfires on newer TJs with the ignition coil rail instead of a distributor.