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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 and tighten 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 6.25 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 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.
I hope this information helps!
Thanks! Glad you wrote this and not me. This should be re-written to include this from the start. Once I read this from the top of this page and heard that there was surging I knew it was due to air leaks. I am a launch manager for a company that makes intake manifolds for Honda. Their manifolds and TB are the same. Nylon manifolds with heat inserted nuts, same gaskets, and drive by wire TB. I can't stress enough that the proper torque sequence be applied or you will strip the inserts and it will leak or gasket will "bunch" at the 4th bolt and leak. If you take the gasket out (or knock it out with a rag or whatever) you MUST put it back in with the tongue (witness tab) first and sliding two fingers around to install the rest of the gasket at the same time. If not that tongue may cause a leak due to improper install. It happens at our leak test every time we get someone new installs them without this method. As for "touching/moving" the butterfly valve, it make no difference, go ahead and move it just don't disconnect the TB or the learned home position must be relearned by the ECU - in all cars. I have seen people in my mechanic days use a rag with straggling bits or terry cloth to clean and leave chunks of the rag in between the TB and valve and it cause high idle also.
I hope someone has the time to retype all this and it get re-stickyed.
BTW many forums have a thread with links in categories to the best threads involving DIY or problems/fixes etc. I will suggest it in the suggestions area.
Thanks! Glad you wrote this and not me. This should be re-written to include this from the start. Once I read this from the top of this page and heard that there was surging I knew it was due to air leaks. I am a launch manager for a company that makes intake manifolds for Honda. Their manifolds and TB are the same. Nylon manifolds with heat inserted nuts, same gaskets, and drive by wire TB. I can't stress enough that the proper torque sequence be applied or you will strip the inserts and it will leak or gasket will "bunch" at the 4th bolt and leak. If you take the gasket out (or knock it out with a rag or whatever) you MUST put it back in with the tongue (witness tab) first and sliding two fingers around to install the rest of the gasket at the same time. If not that tongue may cause a leak due to improper install. It happens at our leak test every time we get someone new installs them without this method. As for "touching/moving" the butterfly valve, it make no difference, go ahead and move it just don't disconnect the TB or the learned home position must be relearned by the ECU - in all cars. I have seen people in my mechanic days use a rag with straggling bits or terry cloth to clean and leave chunks of the rag in between the TB and valve and it cause high idle also.
I hope someone has the time to retype all this and it get re-stickyed.
BTW many forums have a thread with links in categories to the best threads involving DIY or problems/fixes etc. I will suggest it in the suggestions area.
Interested in this procedure can you explain further ...do you mean line up the tongue first and simply slide/pressing around the ring/circle to confirm placement of the rest of the ring? Plus I have seen in other cars when o rings are used etc. the application of dielectric silicone grease - do you recommend a thin layer applied to the o ring?
Last edited by G37sGraphite; 04-10-2016 at 09:29 AM.
You are correct. If you move the gasket you should clean out the groove and gasket as grit build up at the bottom from washing and driving. No grease necessary.
i cleaned my throttle bodies yesterday (@ 30,500 miles), but they weren't very dirty. didn't really move the butterfly, but didn't really need to. no CEL's, no weird idle afterwards ...
pulled out one of the mass airflow sensors to clean those, too, but it was pristine - and i mean, "shiny, like it was brand new". i didn't bother cleaning them.
I had idle issues at 45K. After cleaning the throttle bodies, which were moderately dirty, the idle issues went away. If you notice a little dip in your idle at a stoplight, you are overdue for a cleaning.
I had idle issues at 45K. After cleaning the throttle bodies, which were moderately dirty, the idle issues went away. If you notice a little dip in your idle at a stoplight, you are overdue for a cleaning.
UCLAg37
45K is right when I was experiencing issues as well. Cleaned my TB and every thing is gravy. Cleaned them again at 80k for grins and they were pretty clean.
Id say clean them every 45-50k or if you are experiencing any issues!
For what it's worth I cleaned my TB's over the weekend. I did disconnect the battery because I was installing some Stillen intakes and I also did manually open the butterflies to clean them, but I left everything else connected to the TB's. 105k miles on the car. I didn't have any idling or stalling issues, but figured I'd give them a good cleaning while I was there. Didn't notice any difference after, but I'm sure it didn't hurt. Tightened the bolts down in an X sequence to 75in/lb's. I didn't have to mess with the rubber o rings at all as they just stayed on the intake. I used some TB specific cleaner, a softer bristled brush and a terry rag.
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 and tighten 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 6.25 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 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.
I hope this information helps!
Finally got around to doing this today...I followed the DIY exactly.
The information that I wrote about above from the service manual I followed EXACTLY also.
- My car was at 18k miles and it was not filthy but give it another 18k and it would be a problem. It looked like the perfect time to clean before it got too bad.
I did also do the following:
I opened and closed the butterfly valve multiple times cleaning it. No way you clean it properly without doing this. The blades accumulate gunk on the edges and underneath.
I also decided to change the gasket and made sure that I inserted it correctly as in post #287 above (thanks m3clubracer) explains.
When I turned the car on the RPM surged and RPM was high even after warmed up around 850 RPM or so. However, I followed the Throttle Valve learning position procedure (see above) waiting until coolant reached over 149 degrees. I then turned it off and restarted it after about a minute and sure enough the RPM dropped down to normal around 650 RPM.
Success! Based on this if you follow the instructions in the DIY and Service manual exactly and make sure you tighten everything correctly the moving of the butterfly valves should not be a problem.
Cleaned mine this week, idle was at 600 and would drop to 500 about every stop. Clean idle is ~650 rock solid - definitely worth the time. Such as simple fix for poor idle!
04-10-2016, 07:24 AM
Success! Based on this if you follow the instructions in the DIY and Service manual exactly and make sure you tighten everything correctly the moving of the butterfly valves should not be a problem.
