Ethanol free 87 octane gas, now my TJ is idling high

RedrumRH

RedrumRH

WNC Asheville Area
Supporting Member
Joined
Apr 9, 2018
Messages
233
Location
Mars Hill, NC, USA
TJ has been running great since new plugs, IAC, major tune up etc. Today I put about 12 gallons of 87 octane ethanol free gas. After a short while, might have been next time I started after driving a dozen miles, check engine is on. The engine now idles higher, it was at about 800, and now 1,200 rpm. When I goose it while stopped and in neutral, up to about 2,500-3k rpm, it takes at least a few seconds to go back down to 1,200. Suggestions?

Would disconnecting the battery for a few min reset anything like the way the Idle Air Control, the new tank of fuel must have down something. This was the first tank of pure gas and I would like to run it when I can get it.

Thanks in advance for suggestions.
 
This is 100% unrelated to the ethanol free fuel, that's just a coincidence.

Disconnecting the battery certainly wouldn't hurt. I'm assuming it's not throwing any check engine lights either?
 
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I unhooked the battery. 3 min later......Check engine light was off when I reconnected and started. Drove it on a couple short trips today, Idle is back at 750-800 rpm and all issues gone.
 
Check engine light back on today, and high idle and inconsistent idle around 2,000 rpm. I disconnected battery, took off air intake house from throttle body, sprayed a bit of throttle body cleaner, more cleaning, reassembled and restarted. Engine light still on. Disconnected battery, took throttle body completely off, more cleaner down deep, took off IAC, and gently moved the tip section in and out a couple times. (The IAC module is a new part I installed a week ago. full disclosure, I did not go with Mopar part, went with the one that was a third the cost.........second thoughts?) Reassembled, started, engine light gone, and idle normal.......

I hope the monkeying around with the IAC module somehow helped. Seems the combination of stuff got the check engine light off.

Stay tuned :jump:
 
I got the reasonably price, NOT MOPAR, unit. It was like $25. MOPAR was $50. So maybe if it keeps acting up I will replace with the MOPAR part. My thought also, that I should have got MOPAR original. If it keeps acting up I will get a MOPAR replacement.
 
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