Recently I had a rough idle and harder to start than normal issue on my own personal 2005 Ford F150 pick up truck with a 4.6L V8 engine.
Some common complaints when the throttle body is dirty and needs to be cleaned are:
1. Rough idle speed – shaking or trying to die when the vehicle is at idle
2. Slower starts – the engine seems to start and die or turns over longer than normal
3. Erratic idle speeds – idle speed seem to surge up and down or when you turn the A/C on the idle speed is too low and the engine dies
4. Decrease in fuel mileage
Just about any auto mechanic or oil change mechanic can do this for you, or you can buy a small steel brush and a can of Throttle body cleaner from your local auto parts store and do it yourself.
I would recommend you clean the throttle body about every 30,000 miles as part of your regular scheduled maintenance program.
If you have never had the throttle body in your vehicle cleaned, I would bet you would see and feel a huge difference in the smoothness of the idle speed as well as quicker starting time.
Here is a short video of us cleaning the throttle body on my truck
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How to clean a dirty throttle body
Thank you to Walter Jones and Christian Brothers Automotive center