over reving when at full temp
 

hey guys im new here i have got a 1999 1.6 subaru impreza and have a problem with it when its idling on cold it sits on the revs as it should but as soon as it gets to ful temp it starts to really over rev itself if any one could give me any advice on what it could be id really appreciate it thanks . :thumb:

How is the idle controlled on your car? Is it with an idle speed control valve?

When this happens, usually the ISCV is dirty and gets stuck sometimes - however most times this will raise engine code 24 and you will have a check engine light along with the high idle.

Another possibility is that somehow the idle up and idle down wires to the ISCV could have been swapped around.

Remove your ISCV and clean it first then set the idle speed while warm. Also inspect the wiring to the ISCV for any shorts.

Sounds a bit like your temp sensor and its not cutting the cold start..

yeah the check engine light comes on and looses all the revs then the revs kick up again and will definitly check all the wires to it thanks

yeah i changed the map sensor as got told that can sometimes cause it and thats made no difference will have to look into the temp sensor thanks bud:thumb:

check the error codes.. see my website in the help pages for how to read the error codes
www.jollygreenmonster.co.uk

Simon

thanks for that buddy brilliant information really is but only problem is tht the engine check light dont come on till its running and upto full temp lol

Error code will be stored in ecu unless you switch ignition on and off about 20 times with no engine light

ok thanks alot definitly will be giving your info ago your a star thanks alot bud

hi again guys just a bit of an update i have as you know replced the map sensor and i have also now replaced the idle control valve cleaned up all the intake pipes and still no luck with it atall any more ideas would great thanks again

You have not followed the advice by JGM to check codes.

yeah i have took his advice found out what the codes was and it come up to be code 24 which is the idle control system thats why i changed the idle control valve but it hasnt made any difference atall