Erratic Idle On Start Up When Cold Outside

xrbeav · October 7, 2009

I have searched for a solution and thought I had one. My 2002 Suburban idles very rough/erratic when the temperature outside is cold(i.e. 32 degrees or below). I can hold the idle up, 1500 rpm, via the peddle and it will be fine. But when I let off, it will almost die and then idle varies between 700 to almost stalling. Once the engine is warmed up, it will idle fine. I have taken of the throttle body and cleaned it very thoroughly and also replaced the Idle Control Actuator on the side of the throttle body. Where do I go next? Since it is about cold weather time here, I need to get this fixed. The problem seems to be related to ambient air temp. And like I said, if I hold the throttle open slightly, it will idle smooth and fine. It seems like the high idle for colder weather is not kicking on. I don't know how that is controlled. I thought it was the Idle Control Actuator, but changing that did not affect things. My other thought is MAF Sensor. I just hate to keep throwing money at it in hopes of fixing it. The Idle Control Actuator cost $175. Not a cheap piece by any means. Forgot to add, this started happening last winter, when summer came around it would start totally fine because the temp was warm outside. Now that it is cooler, it is reoccurring.

I know, I should have addressed this before now. Can we say procrastination?

Thanks for looking and any help.

xrbeav · October 9, 2009

Anyone??? Thanks.

redvett · October 9, 2009

Clean the throttlebody and also the MAF with the correct cleaners if that does not work change the CTS it reads engine temps and tells the PCM how to control the engine speed and the amount of fuel needed.