irratic idle rpm speed

[yewtree]

as title says when at idle in park rpm is usually about 700rpm but today was parked up and the rpm started to rise and fall from 700rpm up to 1200rpm the back down again, it done to over and over until i drove off, then parked up again it started doing it again, any advice would be great

thanks phil

 

[LibertyTC]

Start by removing the IAC and cleaning the port while there using throttle body spray cleaner.
The IAC controls the idle.
Also remove the intake hose to the throttle body and ensure the throttle plate is moving freely.
Use the TB spray cleaner there around & inside intake a bit.
49087[/ATTACH]"]

You must be registered for see images attach

49089[/ATTACH]"]

You must be registered for see images attach

49091[/ATTACH]"]

You must be registered for see images attach

49093[/ATTACH]"]

You must be registered for see images attach

49095[/ATTACH]"]

You must be registered for see images attach

49097[/ATTACH]"]

You must be registered for see images attach

It is easy to remove after you crack the screw loose.
First time they are tight and need the ratchet set up to break it free without stripping the Torx 20 screw.
This should restore the idle again Lets us know if idle is good after cleaning!

 

[LibertyTC]

Also when u check the throttle plate ensure that the sides of the throttle butterfly valve is clean.
Often carbon builds up on the outside top & bottom of plate.
I just hold it open by throttle cable & use a Q-tip soaked in cleaner to remove it from the outer edges then.