Ask an expert

Hi,

I have toyota wish 2010 and when starting cold, it idle RPM goes to 1500 and then after some steadies at 1000. it only happens when its cold.

so i think its electronic throttle body needs to be cleaned. it does not have a IAC valve on it. so would like to know, what precaution I should take while cleaning throttle body? people say, do not open butterfly valve using hand when connected onto vehicle so is it safe to remove it from car and manually open butterfly to clean it? I have got throttle body cleaner. and is there any relearning needs to be done after fitting it back on car? and precaution I need to take?

Thanks

Hi there,
This actually sounds like a normal operation of the cold start system, it is similar to an older vehicle when you would activate the choke and the car would rev a bit until the cold system warms up. But now the system is computer controlled.
If the revs didn't increase when the car was cold, it would run rough as the fuel mixture needs to be rich when cold and leaner when hot, and the vehicle would also take longer to warm up. The thermostat operation might need checking in order to make sure the car is not running cold for too long.

Hi Cade,

when its cold RPM spikes at around 1500 and as it warms up, it steadies at 1000 RPM. Toyota guy said, it should be around 800 RPM. and hence I guess, its because of dirty throttle body? and I would like to know, what to keep in mind when removing throttle body from car and cleaning using throttle body cleaner?

I see,
Most of the time you can clean around the butterfly without disassembly, with spray and a cloth. However if you remove it, make sure you are careful with the gasket and any cooling lines that heat the fast idle solenoid that may be there.
You shouldn't need to clear the system memory after this, but sometimes it might be necessary to try and get the computer to re establish the 800rpm idle memory.