2013 5.3 High idle after cleaning MAF & Throttle body

[63Blackseries]

So today after a oil change i decided to clean the MAF and TB with the correct cleaners by CRC, I took off the MAF and sprayed that and left it to dry then i had a friend press down on the accelerator so that the butterfly would open then i sprayed around the edges of the TB and let it dry.

After putting everything back together then starting up the engine it starts up at about 1200 RPM then very slowly backs down to about 500 - 600 RPM i can feel slight vibrations at idle, has anyone experience these problems? do you think i messed up on something? and yes i disconnected the battery to see if it would reset but no change.

 

[GM Customer Service]

Hi 63Blackseries,

I am sorry to hear that you are experiencing an issue with your vehicle. I understand that you are looking to resolve this issue yourself and are looking for advice. I might not be able to provide you any technical support but I would be happy to look into this concern for you. Please private message me if I can be of any assistance.

Jennifer T.
GM Customer Care

 

[CrashTestDummy]

That all sounds pretty normal to me. At least that's about what our '10 does on cold start. Depending on the ambient temperature, the truck can start at 1200-1300 RPM, but will start to drop down to normal idle RPM after about 30-45 seconds of running. A slight vibration at idle is pretty normal.

 

[The Widge]

That happened to me on mine, it will get better with miles and time. I was throwing a code, cleaned everything. Code hasn't returned in two years. Idle came down gradually over a few days and back to normal in a month

 

[63Blackseries]

Update! I went ahead and took off my TB and cleaned it properly then put everything back together making sure nothing was loose, the truck runs much better now everything is smooth and acceleration is responsive and that idle vibration has died down i can barley feel it, only feel it if i pay attention to the engine idling.

 

[North49]

I hope you are disconnecting your battery when cleaning the throttle body. The only way to get it cleaned properly is to remove it and clean the back side and mating edges.

The PCM will reset after several drive cycles however to get good idle immediately you must reset the learned parameters of the dirty throttle body that are logged in the PCM.

My 2 cents .....

 

[Hammer]

The PCM will reset after several drive cycles however to get good idle immediately you must reset the learned parameters of the dirty throttle body that are logged in the PCM.

The dirtier the TB, the longer the relearn. You cannot reset the learned idle airflow values by pulling the battery cable. You will need HPT, Tech2, etc.