Twistedtat

I read somewhere that if you do not disconnect the battery before removing the TB it can mess them up on our cars. Dont really know if its true or not. Anytime you mess with electrical components dis connect the battery first. Also I would look to see if the throttle position sensor is malfunctioning.

Nakamura

Got this one:
P1400 Cold Start Emission Reduction Control System

Will order new TB and keep you updated.

donbrew

Now that's curious. My HHR does not have an EGR valve. The EGR system on these cars is mostly that large "catch basin" under the TB has the effect of cooling the intake.

solman98

I have a question on how you cleaned the TB. Did you manually move the butterfly? I have read that is a big no-no on drive by wire. Manually moving the butterfly will throw the TB off completely.

I recently had to clean mine due to a MAP sensor code that wouldn't go away. What I did: remove TB (leave connection plugged in) and lay a rag over the mainfold to catch dirt. Turned the ignition to run (don't start it). Had wife puch the gas peddle to open close the butterfly while I sprayed the TB. Worked great. Granted, PITA since it takes 2 people. BUt lke I said, I read that you do not manually move the butterfly in a drive by wire.

donbrew

The electrical part of the problem comes from moving the butterfly manually WHILE it is energized.

There are 2 position sensors and 1 position activator in the TB position circuitry. And the same in the pedal. Actually more complicated than you might think.

Nakamura

No, I have removed TB completely from my car while cleaning TB sensor (and disconnecting it from its wire). And yes, I have manually moved the butterfly while cleaning.

And I didn't disconnect negative wire from battery while disconnecting / connecting TB.

It looks like TB works incorrect. In this case I'll order new one (I've got TB related error before all this mess, so TB should be replaced anyway :) )

Nakamura

I have only one question left:
- after installing new TB, should I calibrate it somehow? (I think that closest service station for HHRs is on the East border of US :) so in this case I will sell my car as non-repairing :) )

donbrew

It calibrates itself. The Accelerator Position Sensor may be a problem (and/or).

Twistedtat

@ donbrew. That is some pretty interesting stuff on the TB.

Nakamura

Hi all,

I'm back :)
Installed new AcDelco TB - same sh@t. In idle mode I have 2500-2700 RPMs.

Will check error code that I received after installing new TB and will check default position of acceleration pedal in idle mode.

Checked it with or without MAF sensor / temperature sensor - same in all modes...