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Discussion Starter · #1 ·
2012 Accord LX-P Sedan 4 cylinder with 30,000 mileage

Cleaned throttle body + clean MAF sensor + disconnected battery + "clear all codes" (there were no codes so this would effectively reset everything) with OBDII Torque Android app

Now, the car has an abnormally high idle, surging rpms when coming to a stop, and a abnormally high rpm when backing up in reverse gear (it backs up too fast now!), high rpm when crawling/creeping when I'm not touching the throttle.

Is this just the computer trying to relearn everything? Do I just have to drive more and wait until the computer relearns? From my research, some people say you need to recalibrate the TPS (throttle position sensor)?

Car was perfectly fine in all regards before the cleaning, and yes, all hoses snug and no vacuum leaks.

TYIA!
 

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PCV valve needs replacing?

Did you use the proper solvent to clean the MAF and TB. (You didn't use something like brake cleaner?)
 

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You've broken something. Sounds like you could have damaged the MAF. Do you have the check-engine light on?
 

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The last time I cleab my throttle body I had erratic idle for about 30 seconds. I'm guessing some fluid got somewhere it shouldn't and dried out after I drove a little.
 

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Discussion Starter · #6 ·
PCV valve does not need replacing...has barely been 2 years of owning this car. 2012 Accord.

It's basically still new.

I used throttle body cleaner that I've used on all other cars with no issues at all.

There is no check engine light. I scanned with my OBDII and found no error codes. All DTCs have been completed and passed (ie. O2 sensor, evac, etc.) I've been driving it for about a week. Still feels kinda funky.
 

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Was the idle OK prior to the cleaning?

My suggestion would be to see if you can find a dealer with a used 8G who will let you borrow the MAF for 10 minutes to see if that's the problem. It's a longshot, but a longshot would be better than buying a new one not knowing if that's the issue.

EDIT: and if you have OBDII and Torque, add the air flow display so you can see at idle if it's jumping around. At idle for me it's (I think) around 30 CFM.
 

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Discussion Starter · #8 ·
Was the idle OK prior to the cleaning?

My suggestion would be to see if you can find a dealer with a used 8G who will let you borrow the MAF for 10 minutes to see if that's the problem. It's a longshot, but a longshot would be better than buying a new one not knowing if that's the issue.

EDIT: and if you have OBDII and Torque, add the air flow display so you can see at idle if it's jumping around. At idle for me it's (I think) around 30 CFM.
Hmm...30CFM? Did you change the units under settings to "Use CFM" ? I left it alone and idle it's around 9....which I assume is the default grammes/sec.

What is your engine idle rpm? Around 800-900 right? My car takes a while of driving before idle drops to 800-900, otherwise it hovers around 1500 rpm initially. It's like it needs to warm up before idle rpm drops lower...
 

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Discussion Starter · #9 ·
You've broken something. Sounds like you could have damaged the MAF. Do you have the check-engine light on?
Does a damaged/faulty MAF throw a check engine light? I don't have any check engine lights or codes whatsoever.
 

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Discussion Starter · #10 ·
The last time I cleab my throttle body I had erratic idle for about 30 seconds. I'm guessing some fluid got somewhere it shouldn't and dried out after I drove a little.
Did you have to perform the Honda ECM/PCM Idle Learn Procedure afterwards? http://flashprotuning.com/blogs/vitviper/honda-ecmpcm-idle-learn-procedure

I read that these drive by wire cars acclimate themselves automatically to carbon build up in the throttle body, and that when you clean it, the ECU will take a while to get use to the new change before everything is optimized.
 

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Hmm...30CFM? Did you change the units under settings to "Use CFM" ? I left it alone and idle it's around 9....which I assume is the default grammes/sec.

What is your engine idle rpm? Around 800-900 right? My car takes a while of driving before idle drops to 800-900, otherwise it hovers around 1500 rpm initially. It's like it needs to warm up before idle rpm drops lower...
Yes, I use all english units. CFM, mph, F, etc etc.

In P it sits around 800 rpm and doesn't vary more than +/- 20 rpm.

In D it usually idles around 700-800.

1500 rpm on startup is normal with a cold engine.


Also try clearing the codes, even though you don't have any. That will reset the ECU (or at least it resets all of the emissions stuff).
 

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Discussion Starter · #12 ·
Yes, I use all english units. CFM, mph, F, etc etc.

In P it sits around 800 rpm and doesn't vary more than +/- 20 rpm.

In D it usually idles around 700-800.

1500 rpm on startup is normal with a cold engine.


Also try clearing the codes, even though you don't have any. That will reset the ECU (or at least it resets all of the emissions stuff).
Yep, that's what I did after cleaning the Throttle Body. Cleared the codes even though I had no codes just for the purpose of resetting the ECU.

Also, I found this:

http://www.pakwheels.com/forums/per...3rd-generation-city-accord-owners-dbw-related

Do not clean the throttle body of your cars from anywhere aside from a Honda 3S dealership. The reason for this is quite simple:

- The throttle system on these cars is a fairly advanced drive-by-wire system (DBW) which learns its throttle opening and and idle settings over the period of driving the car. It also adapts to the carbon buildup around the throttle opening over time by a learning process and adjusting throttle sensitivity accordingly.

If you end up cleaning this by yourself or at a non-Honda workshop the results will be as follows:

- The car will lose its idle settings and the RPM will become erratic
- The throttle response will be extremely twitchy and the car will become "nervous" randomly when giving or releasing throttle.
- This behavior will continue and the car will become an irritation to drive until its reprogrammed at Honda

The only way to clean the throttle body is to go to a Honda dealership, where they will clean the throttle body and then reprogram the car's throttle using the HDS (Honda Diagnostic System), this is a 15 minute computerized procedure which you *cannot* replicate anywhere else unless you have the HDS programmed for these cars.
 

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Let's hear it for pakwheels: The quote is spot on.

I experienced the same thing on a 6th gen. Accord. I was able to correct the problem by spraying throttle body clearer into the throttle body while the engine was running. Took about 10 seconds and the rpm's returned to normal, and I experienced no other problems. I took this as evidence that my efforts to clean the throttle body with the engine off had resulted in residue accumulation on the MAP, which was then "cleaned" sufficiently when I repeated the procedure with the engine running. Dumb luck, perhaps.

Let me add that spraying TBC into a running engine is a potentially EXPLOSIVE situation. Use extreme care!
 

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Discussion Starter · #14 ·
So it seems like my only option is to bring it back to the dealer to reset ECM/PCM idle learn procedure and Calibrate Throttle Position Procedure? I am still under warranty...but I'm not sure how they will take it when I explain that my car is acting funny because I cleaned the throttle body.
 

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So it seems like my only option is to bring it back to the dealer to reset ECM/PCM idle learn procedure and Calibrate Throttle Position Procedure? I am still under warranty...but I'm not sure how they will take it when I explain that my car is acting funny because I cleaned the throttle body.
They won't care, but expect a small charge for the effort.
 

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So it seems like my only option is to bring it back to the dealer to reset ECM/PCM idle learn procedure and Calibrate Throttle Position Procedure? I am still under warranty...but I'm not sure how they will take it when I explain that my car is acting funny because I cleaned the throttle body.
yes, we reset the ECTS which clears the stored learned idle position. carbon is now missing so air gets in where it couldn't before - therefore idle surges.

I'd suggest you try this method before possibly loosing $$.

disconnect both battery cables. hold them together for about a minute. reconnect them and turn off all loads. let the car idle for 20 min if the surging is gone so it can relearn.

if that doesn't help take it in and tell them the throttle has been cleaned and the learned procedure has to be reset, not just a pcm reset. it's found in the HDS inspection/ects menu. lol
 
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