Removing the Throttle Body

Having tested the spark in our previous episode and found it satisfactory, I decided to move on to removing the throttle body. The throttle body, for those who don’t know, is the mechanism that controls the amount of air going into the intake manifold in response to how far down the driver is pushing the accelerator pedal. The airflow is controlled by a butterfly and the position of that valve is read by a throttle position sensor attached to the side. This information is sent to the ECU as part of the equation used to figure out the air/fuel mixture to be injected into the engine.

Throttle bodies get dirty, and a dirty throttle body can stick and otherwise not function well. The dirt introduces turbulence into the air stream which can mess up idle and diminish fuel economy. Neither of those things are good, so I decided to take mine off and give it a good cleaning.

Removal was a relatively simple affair, in principle at least. It’s held to the intake manifold with just three bolts. The outer top bolt can be easily removed with a socket wrench. The other two required me to borrow a set of crescent wrenches from a neighbor because the space available to access them was minimal to say the least. Once I had the wrenches I was able to remove the last bolts and take the assembly off.

As you can see in the middle photo, the inside of my throttle body was quite dirty. Unfortunately I did not have any throttle body cleaner on hand, nor did I yet have the replacement gasket. The existing one was also quite dirty and definitely needed to be replaced. That should arrive in a day or so.