Celica Forums Install Guides and Technical Articles Engine and Transmission Guides Intake, Throttle Body - How To Clean

Cleaning The Throttle Body For Better Engine Performance
By hephaestus


Why clean it?
Why do I want to clean my throttle body you ask? What is my throttle body? The throttle body is the piece that the air Intake tube hooks up to. It contains the throttle control plate that opens to control the amount of air flowing into the engine. You should clean this out periodically because carbon will build up inside of it causing a poor idle and sluggish Performance. It is fairly easy to clean, so you should do it. You will probably find it coated with black junk, and will notice a considerable difference afterwords. Every car can benefit by having the throttle body cleaned, especially if your car is idling bad, stalling or lacking power.

The throttle body on a Toyota fuel-injected engine contains a butterfly valve which opens to allow air into the Intake chamber atop the engine when the throttle is open. The throttle body is fed from the air Intake, and after years of use, the particles which get past the air filter can impede airflow, cause idle to drop, or affect the opening and closing of the valve. It's a good idea to clean the throttle body at the first sign of Performance or mileage decreases, and as semi-regular maintenance: I clean mine at every 30,000 mile service.


Tools needed
[*] 8mm or 10mm socket wench depending on if you have stock airbox or an aftermarket air intake system

How to do it
Before you do anything you will want to start the car up and let it get to operating temperature so the dirt in the throttle body will come loose.

Now, what can we use to clean the throttle body? Most carburetor and choke cleaners are pretty strong. The same is true of cleaners that are sprayed into the air intake for combustion chamber cleaning. They have to be strong in order to be able to clean things without mechanical means such as scrubbing with a brush. Sprays cannot clean all areas, particularly the back of the throttle plate. In addition it is almost impossible to see which areas have been cleaned and which haven't.



Can of Throttle Body/Fuel Injector Cleaner.





With your Celica turned off, unscrew three bolts to maneuver the Air Intake enough so you have room to work.



The little rectangle slit in throttle body is where to shot for. It takes some more maneuvering. Pull back the hose covering the throttle body just enough to get the straw in.

Hold onto the little straw to keep it from flying into your engine!

Still, with your Celica off, liberally apply EFI or carb cleaner to the throttle body. Be sure to open the valve to allow the cleaner to work around the valve, and to get some inside the throttle body. (The Toyota FSM specifies carb cleaner for this procedure.)

Spray the little slit and the whole throttle body afterwords.

WARNING: Avoid getting any carb-cleaner on the plastics or rubber parts. Keep a clean rag handy, to quickly wipe down any excess spray. Also avoid spraying your MAF sensor. You should only spray in to the throttle body, not the intake/air-box or towards it.




See the little hole right side. It is located on bottom of throttle body near left center.



Now put everything back together and start her up. It probably won't start right up as it usually does, so don't get nervous. You may notice some white smoke pouring out of your tailpipe; this is normal it will go away once you let the car run for a few minutes and you're done. The white smoke is what is left of the cleaner from doing it's job of removing all the gunk from your engine.

After cleaning I noticed my car doesn't dip down to 200 RPMs or close stall anymore at a stop. In fact I had to re-adjust the throttle cable because I was now idling at 1000 RPMs or a little over from when I tightened the throttle cable some time ago.

This procedure should probably be done once a year as part of your spring tune-up ritual.

Do you do it while your car is running? Yes or no? I've been reading other peoples point of views on the issue and some say no and some say yes, which is it?

just cleaned my throttle body works idles great now!!!

yea do you do it when your engine is running or when its not????

Guys guys guys, you know you should NOT do it while its running, think of the MAF sensor. If its not reading air flow its gonna stall.

How do you clean it running? My 02 will NOT run with hose off, to access tb. I dont advise it, if you can due to maf sensor damage.

I've updated the OP with additional information, to answer the previous questions.