Lucky

I would think if the gears are stripped you would have a tps correlation code.

843de

My thoughts too Oldblue, like I said, these throttle bodies are fragile and a stripped gear would explain the problems guille is experiencing.



If the internal geartrain is damaged, the throttle butterfly will creep open especially under the high intake vacuum generated at idle.

And as noted by Lucky above, I'd suspect a TPS correlation error code to be stored, and the eventual illumination of the CEL.

guille2228

Questions:

1) why does it idle fine when the engine is cold?

2) why when its in gear does it sometimes return to normal until I accelerate?

3) why does the dealer charge soooo much to relearn it? LOL

I've driven around with check engine light on. I think the first time I turned the car on it when on, but then turned off after a while.

843de

All very valid questions, and if you had access to a Tech II scan tool and the ability to interrogate the vehicle, probably answerable in fairly short order.

As to why your dealer charges as much as they qouted you, it's a "prevailing rate" deal, and you might want to call other GM dealers in your area tomorrow to get their rates. A Buick/GMC dealer could do a "relearn" just the same as a Chevrolet dealer can, they all have the proper Tech II's and software access.

Without seeing what codes are stored, and they are easily obtainable by having your local Advance, Autozone, O'Reilly's, Napa, etc., pull them.(about 99% of them will pull them for free)

We're kinda shooting in the dark at a moving target.

guille2228

OK, Mr. 843de. Figure this one out. :)

Took it to Pepboys today and they said there are no codes. I drove it like 15 min to get there, you think something would come up. Guy turned it on. High RPMs and no code.

One think I did notice today is that if I stop at a light for over 3 secs the RPMs are going back to normal. Until, I accelerate. Yesterday, it was just staying rev up .

donbrew

Sounds like gear lube getting gummed up from the cold to me. Or, something stuck in the throttle throat.

guille2228

Donbrew, I had some seafoam throttle cleaner and I went ahead and sprayed it while idle per instructions. I used about 1/2 can and then went for an aggressive drive, per instructions. NOTHING.

Still have high idle. Thanks for the suggestions. PLEASE keep them coming. If it does not go away in a couple of days the dealer will take my beer money away. LOL

843de

Disconnecting the battery in an attempt to trigger the ECM's "Learn Down" mode, would have also cleared any previously stored codes, and it can take 10-15 "Cycles" as GM terms it for codes to reset or self clear.

A Cycle is one "Start, Drive, Shutdown" event.

My guess is that the ECM is attempting to compensate for conflicting reference voltages from the TPS(Throttle Position Sensor) and the APP(Accelerator Pedal Position)sensor. Thereby causing the high idle and odd rpm fluctuations.

You did state in an earlier post that you'd been driving around with an illuminated CEL, was that what triggered the throttle body cleaning in the first place?

You may have had an issue with the throttle body before it was even touched, like a failing TPS or wonky butterfly actuator geartrain.

guille2228

Yes, first time I turned it on after the cleaning the light turned on, but not since. I have disconnected the battery and driven a few times, but not 10-15. Maybe 6. I drove yesterday and today with no CEL light. I drove today and I was sure it would turn on because I drove aggressively. If it wasn't for the RPMs the car drove well.

I'll continue to cycle anytime I go out. See if it helps. Any suggestions greatly appreciated.

guille2228

As an update. I am noticing that when I come to a stop the RPMs are coming back down to normal faster. I still notice that when I'm driven and start slowing down to around 1500 rpms it wants to surge to 2000. It does not do that around other rpms. Still I have notice an improvement.

Still no check engine light. I hope it continues to get better that this is not as good as it will get.

If I accelerate when in PARK the RPMS go up, but are coming down a little faster than before.

Maybe this gives people a little more information on what maybe going on.

Thanks.