AboutTed Ritter Expertise I have more than 26 years experience as toyota technician, I will be able to answer most questions related to the toyota product line up to the present year models, I specialize in difficult to diagnose problems but when posting a question please keep in mind that some situations require the used of special test equipment and diagnostic procedures especially as the newer models become more technologically advanced, so without actually having the car on hand I may only be able to try to steer you in the right direction and in some cases may have to refer you to the toyota dealer but at least you will know what you may be dealing with. Please don't hesitate to ask any questions, I will have an answer for you in most cases. When posting a question keep in mind that I reside in the US, although I get questions from all over the world I may not have an answer for models that are not sold in the US, I will do a reasonable search to try to match your model to the US model,please refrain from asking about diesel powered vehicles, I have no information for them. In most cases I will not answer questions about major modifications of OEM components, engine swapping or aftermarket products,please post a question not a statement, please provide enough basic information such as year, model, what engine and if anything has already been done to fix the problem, the more information I get the more I can help without having to ask you more questions.
Experience Toyota technician since 1979,expert in electrical systems,OBD systems,engine repair, driveability problems,EFI systems,ASE certified,Toyota master technician. Certified Hybrid Vehicle technician.
Education/Credentials Toyota master technician, ASE certified in eight catagories, Hybrid vehicle certified.
Question QUESTION: My 1991 GTS toyota celica has a fast idle (1800 rpm) even when the engine is warm. I have already turned the idle adjust screw all the way down.
ANSWER: Check to make sure the throttle cables are not binding and keeping the throttle plate from closing all the way, check the vacuum hose that goes to the diaphragm on the throttle body, make sure the hose is attached, if the hose is not on it will keep the throttle open a little just enough to cause this problem.
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QUESTION: Thank you for your answer. I checked the throttle cable and all the vacuum hoses and they are all fine. The throttle plate is definitely closed all the way but I still have the high idle, although it does go down to 1000 rpm when the air conditioner is turned on. Help!!
Answer This engine has an idle speed control valve located on the bottom of the throttle body, it may be sticking due to exessive carbon deposits, the throttle body has to be removed to get the valve off, in most cases the valve can be cleaned and made serviceable, check the moving part of the valve inside after cleaning it to make sure it's not sticking, use a small screwdriver to move the valve, it should return to almost close by itself, clean it using air intake spray cleaner and a nylon brush.
