Cleaning throttle body (2002 Corolla CE)

You do not need to remove the throttle body to clean it. The black circular thing that the throttle cable attaches to is sometimes called a bell crank. From the MAF sensor, follow the black plastic tubing toward the engine. The tubing will be connected to the throttle body, which is silver in color and which should have the bell crank that the throttle cable is attached to.

Loosen the bolts or nuts (probably 10 mm) that hold the black plastic tubing on to the throttle body and pull the tubing out of the way or remove it. Spray some carburetor cleaner into the opening of the throttle body and wipe out the inside of the throttle body. Rotate the bell crank by hand while looking inside the throttle body. You will see a circular plate pivoting the middle and expose the back side of the plate. Spray the back side of the plate and the rod that the plate pivots on and wipe out. While you are at it, wipe out as much of the inside of the throttle body as you can.

Replace the black plastic tubing and start the car. You will get some pretty large clouds of smoke until the carb cleaner burns off.

A dealership will probably charge 1/2 or 1 hour labor plus materials to clean the throttle body.

BTW, why do you want to clean the throttle body? Is the throttle pedal sometimes hard to depress? If so, a TB cleaning is in order. If there is another symptom, describe them so you won't be wasting your time.

Ray,

Isn't induction cleaner rather than carburetor cleaner preferred?

Tom

Actually, accelerator seems fine. A year or so ago, I had some odd idling problems which ended up being due to a leaking/cracked fuel injector but not before I learned of other things that cause odd idle. For instance, lately when stopped at a red light (this is an automatic) I noticed the car wanted to 'go' a little more than I thought it should.

So I got home and checked the 'bell crank' and it looked very dirty and gummy. Cleaned it up and figured I would clean the MAF too -- which was dirty -- and wow, throttle response got better, car didn't seem to want to 'go' at a stop, and it idled so quiet I thought the car was dead at the stop light! By the way, I know an automatic obviously goes when you let off the gas but there was a difference between a creep forward and a good forward motion... it now barely creeps forward which is how it was when I first bought it.

So then I figured I might as well clean the throttle body while I was at it.

But yes, acceleration/idle all seems perfect so as you suggest, perhaps it's not worth doing. When it's not broke... probably not worth fixing...

I'm not sure what you mean by "induction cleaner," but the factory repair manual specifies carburetor cleaner.

I know that some automakers coat the inside of the throttle body with something that can be damaged by carburetor cleaner, but Toyota is not one of them.

The throttle plate can stick in the closed position, making it difficult to depress the accelerator pedal. When this happens, a throttle body cleaning takes care of the sticky throttle.

There is also an idle air control valve on the throttle body that controls how much air gets past the closed throttle plate. The IAC valve sometimes gets gummed up, causing rough idle, and a shot of carb cleaner should free it up.