This is my next hurdle. I cleaned the throttle body and now the engine idle keeps racing up high. :/
Cleaned Throttle Body Now the RPMs are too High -- 07 Tahoe
- Thread starter 89Suburban
- Start date
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OP
OP
Thanks I'll take a look under there. But it is really working good now.
Now I got this idle racing issue after replacing the throttle position sensor and cleaning the throttle body. I'll get into more detail later.
swathdiver
Full Access Member
It needs to dry out, something got wet.
PG01
Supporting Member
There is a throttle relearn procedure and it’s supposed to be done before giving it any gas above idle. It will take a while now but it should, should, settle down after a few miles of all types of driving but be careful and stay back from cars in front of you or plan to brake earlier than normal. Good luck. Ill try to find thread that i used after doing mine.Thanks I'll take a look under there. But it is really working good now.
Now I got this idle racing issue after replacing the throttle position sensor and cleaning the throttle body. I'll get into more detail later.
Quick google search came up with this:
https://www.performancetrucks.net/f...ing-161/08-silverado-throttle-relearn-527058/
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OP
OP
Thank you for your help. Excuse my ignorance but I am new to all this technology. My experience being only up to the TBI era. Can you translate what they are saying into something simple I can understand for my dumb ass? I do have access to an Actron OBDII Auto Scanner but I do not know how to operate the more complicated functions or if it is even able to be used to fix this or make it "re-learn".
Here is the timeline of what went down if it helps:
2007 Chevy Tahoe 4wd 5.3. 300,000 miles. I took ownership of it about 3 weeks ago. Ran fine. It originally had a TPS and oil pressure code stored in it. So 2 weeks ago I replaced the TPS sensor on the throttle body. It ran the same and still threw the code once in a while. I saw no defects in the wiring or plug. I did notice the inside of throttle body was very build up with gum and varnish. This is when things went down the crapper. I pulled the throttle body this weekend and removed the new sensor before cleaning it. Took a while to spray and wipe all the black crud out of the throttle bore and plates. It was really caked in there. Now nice and shiny and clean. Reinstalled sensor. Put together. Started up and idled normally. But soon after the first test drive the idle started acting up. Seems like light throttle pressure would make the engine surge in gear, also straining and downshifting coming to a stop. Once you stop it settles down to a normal idle. Then it is fine and you can throw it in park or neutral. It will idle fine basically until you blip the throttle and it starts racing again. If I notice it I quickly enough I can put it into gear to settle it back down. If I am too late I have to shut if off because it's racing 2 -3 K rpms in park/neutral.
I performed this maintenance on Sunday afternoon. The battery was disconnected during this process. I figured it would re-learn on it's own after driving for a while which it seemed to do on Sunday night. Monday morning started fine, drove to work. Get done work and leave the CEL comes on and it starts racing again. Very frustrating and unnerving. Makes me wish I never touched anything to begin with. :/
Certainly cleaning the bore made this thing start acting up.
Here is a picture of my baby, need to get her fixed.
PG01
Supporting Member
Really meant this part...without scan tool im not sure about with scan tool to be honest... i dont have one......i hoped this may of helped you
Without Scan Tool - Learn Procedure
Important: Do NOT perform this procedure if DTCs are set. Refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: A L L Diagnostic Trouble Codes ( DTC )\Testing and Inspection\Diagnostic Trouble Code Descriptions).
Start and idle the engine in PARK for 3 minutes.
With a scan tool, monitor desired and actual RPM.
The ECM will start to learn the new idle cells and Desired RPM should start to decrease.
Ignition OFF for 60 seconds.
Start and idle the engine in PARK for 3 minutes.
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.
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.
Without Scan Tool - Learn Procedure
Important: Do NOT perform this procedure if DTCs are set. Refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: A L L Diagnostic Trouble Codes ( DTC )\Testing and Inspection\Diagnostic Trouble Code Descriptions).
Start and idle the engine in PARK for 3 minutes.
With a scan tool, monitor desired and actual RPM.
The ECM will start to learn the new idle cells and Desired RPM should start to decrease.
Ignition OFF for 60 seconds.
Start and idle the engine in PARK for 3 minutes.
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.
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.
swathdiver
Full Access Member
I used to love watching my Grand Nationals go through the relearn idle procedure. Every time we disconnected the computer it had to relearn how to idle and in a few minutes it was ready to be driven. The motors would barely run, then idle up, then barely run, then idle up, each time getting closer and closer together until the motor purred... those were the days!
OP
OP
None of this is working .
PG01
Supporting Member
I think it may be a matter of time now, driving, Resetting cel, driving, resetting cel. Unless that tech2 can do it but im not sure. Sorry man. I told someone else on here about the relearn and im not sure what ended up happening but they were going thru the same thing. Ill see if i can find the thread. While i do that, start a new thread with relearning idle on an 07 tahoe, maybe soneone knows how to yse the tech2 or a beter wayNone of this is working .
OP
OP
Let me ask you this. When you remove the TB and remove the TPS sensor there are 3 gears in there. One is on the throttle drive motor thing, looks tiny like a pinion gear. Then there is a big white middle gear. Then a smaller black gear attached to the butterfly shaft. During my cleaning process the middle white gear popped out. Is it possible those gears are not synced? Is it possible as while I was holding the butterfly open by hand and that white gear popped out that the drive motor pinion gear moved out of its normal position? Does that drive gear have a self centering position? I also looked at the white gear when re-assembling and noticed some teeth were slightly worn so I clocked it to drive on the less worn teeth.
