Your throttle body is a very important and commonly neglected part of the engine. A dirty throttle body can cause delayed throttle response, hard gas pedal, and a high or wavering idle. Cleaning the throttle body is a simple procedure and just about the same on every car.
Function of a throttle body: A throttle body is a “throat” that has a butterfly valve. Most cars run on about 15 parts air and 1 part gas that get mixed and combust. The throttle body and the butterfly valve control how much air is put into the mixture. The harder you press the gas pedal, the more the butterfly valve opens. When you floor it, this is called “Wide Open Throttle” and it allows maximum airflow.
A cleaner. I recommend SeaFoam Deep Creep cleaner. If that is not available, the cheaper alternative is GUMOUT Carb/Choke Cleaner.
Rags of paper towels.
A screwdriver. One Phillips to unscrew the hose fastening, and one very large one to hold the throttle open.
Alright, let’s get started.
To locate your throttle body, find your air intake. Follow the hose up to a metal structure, that’s it. There should be a clamp holding the hose down to it.
Diagram of Engine: (This obviously varies.)
Step 1: Take out your air filter and inspect both sides of it. If it is dirty, slap it against the pavement to knock some dirt out. If it is very dirty, time for a new filter. This affects performance.
Step 2: Unscrew the air hose that is connected to the throttle body. It is usually fastened by a hose clamp that is easily removed with a Phillips screwdriver. The hose may be hard to take off. Just make sure you unscrewed it all the way, and yank until it comes off. You have now exposed the throttle body (DO NOT DRIVE LIKE THIS!). My throttle throat is relatively clean, I cleaned mine out a few weeks ago. Picture of exposed throttle throat:
Step 3: If you haven’t done this in a very long time, there is a good chance the body is charcoal colored. This gunk builds up over long periods of time. There might also be a small hole inside the body. This is called the IAC, or Idle Air Control Valve. It isn’t always located here, I’m not sure where else it could be. (I could use some clarification here). In my Toyota Camry, it’s located inside the throttle body. A dirty IAC valve can cause my Camry’s engine to go haywire, so I recommend cleaning it out also.
Step 4: Attach the spray straw to the cleaner you are using. I will be using GUMOUT Carb/Choke Cleaner. Make sure you don’t drop the straw into the throttle. With the butterfly still closed, spray the cleaner in the body and scrub away with the toothbrush. The gunk should let go pretty easily. Wipe away excess with a cloth or paper towel. Clean the top of the butterfly valve also. When you are sure it’s clean, move on to Step 5.
Step 5: This might be a little tricky. Using a large screwdriver, you need to find a way to prop the throttle open. Example:
With the throttle wide open, the inside of the throat should look like this:
Step 6: Look how dirty it is back there! Spray cleaner past the butterfly valve and scrub with the toothbrush. I know you won’t be able to reach inside there and wipe the excess, so just spray it clean as best as you can. Don’t worry about spraying too much, it will just burn away and it is perfectly safe for the engine and exhaust.
Step 7: Close the throttle and reattach the intake hose. Put the black terminal cable back on the battery and try to start the car. Keep your mask open in case anything goes haywire. The car may not start a few times, and it will most likely stutter at first. This is normal. Smoke may also billow out of the exhaust. Only a tiny bit will come out if you used the Carb Cleaner. If you used the SeaFoam, white smoke will come out in LARGE amounts. If you live in an area where people would get angry, do this at night. Let the car run for a few minutes so that all the excess cleaner fluid burns away. You can also hold the car at about 2k RPM to speed up the process.
There, you’re done! Next time you go out for a spin you should feel a better throttle response and you may also idle lower. When I did this the first time, my throttle was dark black. I idled above 1,000, and dropped to 750. Something this simple can really make a big difference.