Altezza Unstable Idle

[joe altezza rs]

im still stuck!

I took the Battery lead off last week (for about 10 mins) and since then the engine wont idle where it should. the needle bounces around 2000-2500 ive been told that the ecu is self learning and normally settles the idle within 5 mins but its been a week now. the car spent the day at my local garage yesterday the computer showed no faults and he cant fix it. i have noticed that if i remove the Battery and reconnect it the car runs fine untill i switch off ignition and start it again. im thinking that there may be a blown fuse or something like that.

ive trawled the internet for any problem similar but cant find anything.

[sparkystav]

Is your fan on all the time?

If the water temp of intake sensors are faulty but not broken then could be causing the fans to run all the time highering the idle?

Get an OBDII connected and look at all the sensor values for anything that looks out of place.

Stav

[Jack300]

It's not the Idle control valve playing up is it? I've just given my 2Ps worth re the opposite problem ie revs drop away and it stalls. If the valve is sticking closed then you'll get the problem you describe. Remove the valve and clean the valve part with either WD 40 or carb cleaner. Only other thing I can think of is air leaking past an injector.

I could be miles out here but I've been fixing my own cars for what feels like millions of years, and if it was a Saab then it'd be one of these two items. Lexus ownership has only been 6 months so forgive me if I'm wasting your time.

Good luck

jack