06Pursuit

iTrader: (1)

So let me begin by saying that yes I cleaned my TB and yes I opened and closed the throttle plate and no I didn't read the warnings about this before hand.

As many of you are aware, cleaning the throttle bodies on our cars usually (90%) ends up with the idle being thrown up. This happend to me. I used Seafoam spray to clean out my engine, this involved me manually opening the throttle to get in there. I also used Throttlebody cleaner to clean up the carbon build up around the throttle plate.

Well after all was said and done my idle was kicked up to around 1500-2000rpm. As any person would guess, I turned to the internet for a solution. As I searched around, I started to see a very specific pattren. People who had their idle jump pass 2000 rpm, royaly effed their TPS and sometimes had to have it replaced then PCM reflashed. This was the extreme case and only happend to a small few. The majority, like me, had the rpm in the 1500-2000 range. In all these cases, not including the ones who took it to the dealer right away for a reflash, the solution was TIME!!

Our cars are equiped with an adaptive PCM that "learns" our driving behaviour and adjusts tables to match. When you force open a "fly-by-wire" throttle body, the rest zone goes out the window and the idle goes to hell. The only way to fix this is to either get the PCM flashed to stock or to allow the PCM to find the normal idle again.

Now onto the best solution IMO. The best way I have found to bring the idle back down, is to force it. If you have a manual car, put the transmission in first with the e-brake up and slip the clutch until the idle is around the normal level. Do this multiple times and the idle will eventualy stay there. Sometimes it will stay until you hit the throttle then it will jump back up again, don't worry mine did this too, just keep true and eventually it will stay. It will take some time, mine took 3 days but now the idle is normal and the car runs great. If you have an automatic, my suggestion is to put the vehicle in drive with the a/c on. This might bring the idle low enough but chances are, a reflash may be your only solution.

Sorry for the long read, but I felt a write up needed to be made!!

YelloEye

iTrader: (3)

Did that fix your high idle problem?

Only solution I've ever seen is to replace the throttle body, had to do it on my friends 2.2. Haven't heard about the reflash bit, unplugging the battery will baseline the ECU back to whatever the currently loaded tune is and get rid of any adaptations.

lsjion

The only thing I can think, is maybe try a battery reset. Maybe its rested posistion has changed since its clean now, or it doesn't recognize it since you opened it while it was connected. I've done it plenty of times connected and not.
try disconnnecting the battery or clear codes, even if there are none, it will reset fuel trims also.
then let it idle with all loads off, radio/ac/lights and such.
Kind of like an idle learn. worth a shot

YelloEye

iTrader: (3)

Used 2.2 TBs are cheap here, if you can't get it to work with the above help just buy a used one that hasn't been molested.

06Pursuit

iTrader: (1)

Disconecting the battery doesn't help as it doesn't erase the learn values on the PCM. the only solution is to wait it out or force it down as I stated. Sometimes getting another TB doesn't do it either as the learn values of the high idle are still on the PCM and a new throttle wont overwrite them.

Gelladuga69

iTrader: (4)

I had a 1500 idle after cleaning my TB. Just drove for a bit and the car eventually fixed itself.

riceburner

iTrader: (66)

if you ever need to replace the throttle body do you need a reflash?

09CobaltSS1

Technically yes. There is a small throttle relearn procedure that should be done so the pcm and tb can accurately match one another with throttle plate position.

YelloEye

iTrader: (3)

According to the 2009 service books.

DSmastery

iTrader: (5)

mine does the high idle after a cleaning, but after i put some dirt back(put some miles on the car) on it the idle goes back to normal


it didnt do it the 1st time i did it as i didnt move the butterfly door. most the dirt is there tho haha

09CobaltSS1

That's a tad tiny so here's something a little easier for us blind folk.. lol

Procedure 4 Throttle/Idle Learn
Description
The engine control module (ECM) learns the idle position of the throttle plate to ensure the correct
idle. Anytime the throttle body is cleaned or replaced, the ECM must learn the new throttle
position. The idle may be unstable or a DTC may set if the throttle position is not learned.
Conditions for Running the Throttle Learn Procedure
• DTCs P0101, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0506, and P0507
are not set.
• The engine speed is between 450-4,000 RPM.
• The manifold absolute pressure (MAP) is greater than 5 kPa.
• The mass air flow (MAF) is greater than 2 g/s.
• The ignition 1 voltage is greater than 10 volts.
Throttle Learn
Important: Do NOT perform this procedure if DTCs are set. Refer to Diagnostic Trouble Code
(DTC) List - Vehicle.
1. Start and idle the engine in PARK for 3 minutes.
2. With a scan tool, monitor desired and actual RPM.
3. The ECM will start to learn the new idle cells and Desired RPM should start to decrease.
4. Ignition OFF for 60 seconds.
5. Start and idle the engine in PARK for 3 minutes.
6. After the 3 minute run time the engine should be idling normal.
Important: During the drive cycle the check engine light may come on with idle speed
DTCs. If idle speed codes are set, clear codes so the ECM can continue to learn.
�� If the engine idle speed has not been learned the vehicle will need to be driven at
speeds above 70 km/h (44 mph) with several decelerations and extended idles.
7. After the drive cycle, the engine should be idling normally.
�� If the engine idle speed has not been learned, turn OFF the ignition for 60 seconds
and repeat step 6.
8. Once the engine speed has returned to normal, clear DTCs.

06Pursuit

iTrader: (1)

Of course not everyone has gm scan tool to do this

06Pursuit

iTrader: (1)

Possible fixes:
1. Idle for 3 min turn off for 1 min. Do this 3 times. - from the forums and sites I visited, this has a zero success rate.

2. Disconnect battery for x amount of time. - zero success rate.

3. PCM reflash - 100% success rate, but can cost $50-$150 depending on the dealer.

4. Time - 90% success rate. Failure comes to those who's idle is higher then 2000rpm I've found.

5. Forcing the idle down via clutch - 100% success rate. This worked for me. Goes with #4.

YelloEye

iTrader: (3)

Do not need the GM scan tool with the process I listed.

09CobaltSS1

Even though both say to use a scan tool one is not needed to actually complete the relearn. It is merely used to monitor and compare desired rpm vs actual rpm.

corski67

Dear 06Pursuit - Thank you!!!

I just went through a maddening sequence of events after a TB cleaning. There are a ton of theories on this site as to how to fix this problem and yours is the only one that works.

Just to dispell all the wrong theories about moving the throttle plate (butterfly valve) while cleaning - Yeah, I did that a LOT. I moved that sucker all over the place... Hell I even removed the screws just like I've done on my Fords for years. Unfortunately it does no good to remove the screws because you can't get the plate out no matter what you do... I digress... Anyway, the idea that the throttle plate cannot be manipulated while cleaning without screwing up the entire unit is pure hogwash. It will however give you the dreaded "high idle" problem in this thread. I also hosed it down liberally with TB cleaner. That too seems to be OK now that I've gone through the "cure" procedure outlined earlier in this thread (#5 above).

Only after going through a series of clutch dragging engine slow downs did it finally cooperate and regain its brains. OK, it's a computer but it's not a very good one if it can't recalibrate after a simple TB cleaning. Seems like some seriously flawed engineering and ECU coding to me.

Bottom line - Follow these procedures and drive the car through it. It will go back to normal eventually.

06Pursuit

iTrader: (1)

Glad I could help!

05g5

i really was a lucky one when i cleaned my TB. i unplugged and unbolted. took out, had prolly 4-5 beer while i played with it and cleaned it. put it back it and car was 100%

cobaltgods were with me that day apparently

06Pursuit

iTrader: (1)

Haha yes I do believe there are times the car ISN'T plotting against you

tomj77

iTrader: (2)

I've manually opened throttle plate and I never got a high idle

startingline05

iTrader: (3)

Sorry to bring up a dead thread but when you had the high idle problem did the car idle higher(2000rpms) when you were say slowing down for a red light or something and when you finally came to a stop it idled lower(1500rpms)?

06Pursuit

iTrader: (1)

No it only jumped when the clutch was in. Had to force it down by riding the clutch

skyline26

i have an auto 2.2 and im having this issue. When idle the rpms are below 1000 which is good (idle before cleaning it was at 1000 or just above) so thats a plus...but when driving the rpms stay pretty much like cruise control is engaged. In Neutral the rpms jump up by itself, but if i put it back into Park or Drive and not moving the rpms drop sloowwly but below 1000.
Just the decel is ridiculously slow holy crap, im gona wear out my brakes so fast.
I did the relearn procedure from GM with no luck, i also DC the battery for like 15mins or so and same issue.

06Pursuit

iTrader: (1)

It's not going to happen over night. An ecu relearn can take up to 40 run cycles

abelimon

I don't know if this is the same a silverado but i had the same happening to me and some where found that if you disconnect neg battery cable and then press on the brake 4-5 times then reconnect neg battery cable. Worked like a charm. This after two days of trying all the relearn steps. I have since cleaned throttle body once a year since and the steps above fixed it first try. Good Luck.