Lots of reading, and YT videos, and I hadn't heard/seen any mention of this 'lip' around the butterfly opening.

Weather and work schedule, finally, allowed me to get my TB cleaned, today. Love the smoother idle, and lack of hesitation when coming to a stop.




Where the butterfly seats inside the TB opening, there's a 'lip' (marked in red), for lack of a better name for it. Pay close attention when
cleaning that you get that area completely clean. If not the build up will hold the throttle open, slightly. The longer you go between cleanings,
the more this will build up with carbon.

 

b12 chemtool is ur friend

 

I would use TB Cleaner only, it works perfectly.




Old school carb & choke cleaner doesn't cut it very well.

Fuel additives will not clean your TB as no fuel runs through it. Modern TBs are exclusively air only valves.

 

Doc, That's a work of art! I use CRC 05078, shop towels, soft brushes, and a beer or 2.

 

Grandpa that is one nasty throttle body. It will cause problems including going into loss power mode. It happened to me twice and never near that dirty. Doc, that is one spiffy clean TB! Better than new.

 

Yeah. I knew there had to be a reason for the inconsistent idle.
Practically, wore out a toothbrush, too.

 

Keep in mind on the newer ones esp the alpha you may or may not need to do a throttle relearn procedure (using a tech2 or hptuners).
Symptoms for needing this would be a stuck higher idle rpm/slow rpm drop after a rev. I had this happen once on my alpha after I cleaned it the first time in 60K and driven 150 miles. I did the I5 several times (06) and never needed the relearn.
Basically throttle blade position needs to be reset so the pcm knows where it sits exactly.