Electric throttle control actuator AKA Throttle body.
In studying the service manual (2013) very closely I discovered some things that are not mentioned that may or may not make a difference in the cleaning of the throttle body and then the associated problems with idle etc. Note: Normal Idle is 650+-50 so approximately 600 to 700 RPM.
1. Do not disconnect the battery. It does not state to disconnect the battery in the Service Tech Manual. Why I dont know. I speculate that although the power is off the the "electric" throttle control acutuator may still be monitoring/recording the position of the butterfly valves. If it is disconnected it will not monitor it and when you start the car the ECU will not like what it sees. Again this is speculation but the manual does not say to disconnect the battery.
2. When removing the Electric Throttle Control Actuator, DO NOT REMOVE anything connected to it. This includes the two water hoses and the harness connector. Service manual states if you remove the harness you will need to do multiple relearns for the ECU.
3. There is a specific order to loosen mounting bolts.
Per manual:
-loosen bolts in reverse order as shown in the figure:
-Tighten in numerical order as shown in the figure.
So I suppose that its 4321 and then tightening it back up 1234.





4. Torque of these bolts is 8.43 FT-LB if you overtighten or undertighten could cause an air leak and ECU again will not like what it sees. (make sure your throttle body and rubber O ring is seated properly you know why....)
5. Do yourself a favor and buy a torque wrench and a Hex Bit Socket Set. Or the socket Hex bit metric 5 if you can buy independent. The whole set only costs around 15 bucks and believe me you will use it again.
6. Service manual states you MUST do the following after you clean the electric throttle control actuator inside.
THROTTLE VALVE CLOSED POSITION LEARNING : Description INFOID:0000000008161734
Throttle Valve Closed Position Learning is a function of ECM to learn the fully closed position of the throttle
valve by monitoring the throttle position sensor output signal. It must be performed each time harness connector of electric throttle control actuator or ECM is disconnected or electric throttle control actuator inside is cleaned.

THROTTLE VALVE CLOSED POSITION LEARNING : Special Repair Requirement
INFOID:0000000008161735

WITHOUT CONSULT
1. Start the engine.
NOTE:
Engine coolant temperature is 25°C (77°F) or less before engine starts.
2. Warm up the engine.
NOTE:
Raise engine coolant temperature until it reaches 65°C (149°F) or more.
3. Turn ignition switch OFF and wait at least 10 seconds.
Check that throttle valve moves during the above 10 seconds by confirming the operating sound.
>> END


So the main speculation is should you move the butterfly valve I do not know. It appears that if you follow the DIY video on this forum and make sure you do exactly what the service manual states ..above... you should be able to move the butterfly valve and have no problems.


Also just a note has nothing to do with the above:
There is a specific removal and replacement of Engine cover bolts. Torque of engine cover bolts is 5.5 FT-LB

 

Truth.

I cleaned both TBs yesterday along with MAF sensors. Moved butterfly valves to clean around and behind. No problems at all. Slight stumble on first startup, but I've always seen that on any TB I've cleaned.

 

Great, but if you read the DIY thread which is like 15 pages long 50% of the people had problems with surging and incorrect idle after cleaning and moving the butterfly valve or they fugged up something else in doing it..... Did you unplug the battery?

 

True, but that is while the ECU is actively monitoring the butterfly valve and in its normal state of operation. I can only speculate that when people take it off clean it and change the exact position of the butterfly valve (when the engine and ECU are not active) that it may start in a slightly different position afterwards on startup and then the ECU apparently does not like that. This is why the manual..states the following: Throttle Valve Closed Position Learning is a function of ECM to learn the fully closed position of the throttle valve by monitoring the throttle position sensor output signal. It must be performed each time harness connector of electric throttle control actuator or ECM is disconnected or electric throttle control actuator inside is cleaned.
..

 

Some very interesting "facts" in here lol.. The car is obviously going to start up with a slight idle issue since the last time it was idling it was dirty with a different amount of air flow and throttle response.. It will obviously have to adjust for this. You cant expect it to start up and just know its been cleaned, if there's no affect on startup then you probably didn't need to clean it or didn't clean it enough.

 

Truth...but in the DIY..people had idle over 1k for weeks until they went in and had it fixed...I suppose they did something wrong...I was just trying to make sure that from every angle we're doing it right per the tech manual.

 

I just recently cleaned my TB I took them off the intake manifold without unplugging them and went to town. The side that is held together with the Allen screws is where all the buildup is. I opened the butterfly's and clean all inside them. The reason I did this was because my car was stalling randomly when I would start it. After cleaning them the car stopped stalling on me. I got a little scared because when I first started the car after cleaning them it idled From 1k to 2.5k for about 5 seconds and then dropped back to under 1k and stayed like that. Idk why it did that but the car has been fine since cleaning them. If my car wasn't stalling out I wouldn't of done it, so unless you really need to do it I personally wouldn't do it because other then fixing my initial problem it didn't do anything else as far as performance.

 

I also cleaned my throttle bodies just last night. Truth be told I went IN on the butterfly valve. Really didn't care because the buildup was so thick I didn't want to risk leaving anything in there. Didn't disconnect the battery or any other hoses for that matter. Allen screws were almost completely corroded from never being messed with over 74k miles. Put it all back together and it started up a little high, but after two minutes it corrected itself back down to 750rpm.

For me, the difference was night and day. Shifts are so much smoother on a 7AT and the throttle is much more responsive. Took about an hour and a half with the help of my better half, and that's only because the damn allen screws took some serious force to undo.

 

Here is why some people have a high idle after cleaning the TB:
-It was VERY, very dirty.

Over time, the TB must be open a crack more (to compensate for the carbon build up slightly blocking airflow) to allow the proper amount of air to pass for idle.

Once they are cleaned, there is MUCH more air passing through and this results in a higher idle.
Perform the required idle air volume, and closed position learning to "set" the new required position for a proper idle.

IF there was a little bit of carbon, the ECU can automatically adjust the TB. If there was a lot, it can't and you now have a high idle.

Keep in mind, the TB function is UNIQUE to the VQ37VHR due to the VVEL. Our TB are only closed at idle, and when we take our foot off the accelerator. (they may also close for a moment with the auto when changing gears. I have a 6MT so I can't verify)

Last item:
When opening the TB butterfly: Open it very slowly!
If you open them quickly you are spinning the actuating motor and that will generate a current that needs to be absorbed some where. Faster you open TB, more chance of damaging the butterfly control.