[Trentjarred]

Guys, need some advise.

R20A1 in a CRV manual transmission. While doing a minor service, I took out the MAF sensor, sprayed it down with electrical parts cleaner, left it to dry. While in there, I used throttle body cleaner to clean butterfly (back and front), thing came out super black, I did not have the car running to spray the cleaner inside. Cleaned out the air box and hoses. Installed a new filter. Car starts fine and pulls smooth as ever (better then before actually).

Issue I’m having now, when rolling in neutral the revs are constant above 1500rpm. When I come to a stop, it returns to normal 850rpm.

I read online that the ecu needs to “relearn/adjust” to the now increased airflow after some time.

Is this true? Did I wake up sleeping dogs? While cleaning did I move the gunk to the idle control valve?

Help.......

 

[Carbuff2]

Do the Idle Learn Procedure. It's easy.

Lets hope that you didn't damage any sensors by spraying...that is NEVER recommended with Hondas. Always just WIPE.

Post back with your outcome.

 

[Trentjarred]

Thanks. In the middle of the idle relearn process. Will keep updating.

 

[Carbuff2]

FWIW, a few years ago I cleaned the TB in our '06, but ! either got busy or lazy and didn't do the ILP. I hoped it would 'learn' on it's own.

It didn't...so after a week I performed the procedure properly and it's been fine.

 

[Scott091981]

What is the normal high idle on a cold 2009 2.4L?

I swapped my battery and did not do this, but it idles at 1500 or so until warm than drops down to 750-800 which I felt is pretty typical.

 

[Carbuff2]

^^^ Typical. Duration of high idle depends on ambient starting temperature.

Failure to perform the ILP results in high or erratic idle when the engine is warm.

 

[Trentjarred]

Well as it turns out, never clean the tb without doing your homework. I found a very detailed post of owners of the 8th gen civic.

This is a common problem, after cleaning out the tb, it is vital to clear out the pcm (reset). By doing that, you will clear out the tps (throttle position sensor) thus enabling it to relearn the idle values.

here is the link to the post, hope this info will assist owners with this problem in the future.

Fluctuating Idle after cleaning Throttle Body

Please Help and Shed some insight. Fluctuating Idle after cleaning Throttle Body. -------------------------------------------------------------------------------- So i decided to clean my throttle body on my 07 civic si coupe(wish i never did),What i did was I took off my intake and wiped the...

www.8thcivic.com

 

[Carbuff2]

Interesting...and here is the best response in the link you provided:

this action has to be done by the use of a scanner and no it doesn't have to be a hds from honda it could be any good scanner with bi directional controls a $100 scanner from the parts store wont work...so if you clean your throttle and notice your idle stays at 900 rpm and when you come to a rolling stop in neutral your rpms shoot up to 2500 rpm till you come to a complete stop or you use your front window defrost and throw a p0507 "idle higher than expected" all these problems are caused by the same problem "TPS CALIBRATION"

Here is a scanner OBD tool that was verified to calibrate the TPS:
a $162 Foxwell NT510. from Amazon. (2016)
Another is a 40$ OBD2 scanner (Konwei KW808). (2018)

Yes, you still need to do an ILP afterwards.

Another notable tidbit from that topic: If you clean the TB on a regular basis, before the ECU 'compensates' for built-up dirt, the TPS calibration isn't really necessary.

 

[Trentjarred]

Final update. Had the TPS reset. Done the idle relearn process. He is riding perfect. Immediately took it on a longish trip 75 miles (120km), got 39.8mpg (5,9l per 100km).