Cleaning the throttle body
From Wiki
A common problem with the gen 6 Celica is a sticky accelerator. There is resistance when you initially press the pedal but after that resistance is overcome it’s fine. The stickiness fades when the car has been driven a bit, but returns the next day after the car has sat for a while.
It’s caused by a build up of black gunge inside the throttle body around the butterfly valve.
Cleaning it out is a simple job that, with experience, can be done in 10 minutes.
To get to the throttle body the inlet ducting has to be removed, but this isn’t complicated. These instructions and photos are for a facelift UK GT, but other variants are very similar.
The resonator (ringed in yellow) needs to come off first. There’s just one hose clamp (ringed in blue) to slacken off and then just pull it out. The bottom just sits in a rubber grommet.
The inlet duct, the top of the air filter box and the plastic chamber to the rear can all come off as one piece now (ringed in red). Undo the 4 clips holding the top of the filter box, pull out the sensor (ringed in blue) that’s just pushed into a hole on the back of it, slacken the hose clamp (ringed in blue) at the throttle body end and manoeuvre the whole thing out. As you lift it away you will find there is a rubber hose, about 20mm dia, connected to the bottom of the inlet duct. This is just a push fit and can be pulled out.
With these bits out of the way you can now see what needs doing. Look down the mouth of the throttle body, open the butterfly valve by rotating the lever on the side and you will see a build up of black gunge. You will make life easier if you can find a clamp to hold the valve open for you.
Cleaning can be done with rag. For anything that won’t just wipe off, a solvent will help. Petrol or white spirit will do the job, but proper carburettor cleaner will do a better, quicker job. (e.g. Wynn’s Air Intake and Carburettor Cleaner, available from Halfords, about £5 a can.) For really stubborn deposits an old toothbrush makes an ideal scrubbing brush. Try not to let any of the dirt/solvent go down the throttle body and therefore into the engine, although small amounts won’t do any harm. But don’t lose any rag or a toothbrush down there. That will be a problem!
Warning - Petrol, white spirit and carburettor cleaner are all flammable liquids and there are several potential sources of ignition in the engine bay. Be careful.
Time to put it all back together. The inlet duct, the top of the air filter box and the plastic chamber can now be replaced, remembering to push the rubber hose back into it’s hole on the underside. Do up the 4 clips around the air filter box and push the sensor back into it’s hole at the rear. Do up the hose clamp on the throttle body, refit the resonator and do up the hose clamp on that.
Tidy up, and you’re done.
--Silver gt 19:58, 18 September 2008 (BST)
