High Idle help please

[bas]

I recently cleaned the throttle body but now the engine is idling too high.

It currently idles around 1100-1200RPM whereas it used to sit closer to 700RPM

I have adjusted the idle via the screw on the TB but its at it lowest limit, I have also re-set the ECU.

[Taz]

Did you clean out the stepper motor when you did the throttle body?
If that is screwed I have 2 spare to sell.

[silverGPX]

make sure the accelerator cable isnt adjusted too tight and pulling the butterfly open a tad

[Taz]

make sure the accelerator cable isnt adjusted too tight and pulling the butterfly open a tad

That too, although i assumed he did this when he adjusted his idle - might be jumping the gun though!

[silverGPX]

also you could have a vacuum leak

[bas]

make sure the accelerator cable isnt adjusted too tight and pulling the butterfly open a tad

Yes I have made sure the throttle cable was not too tight to open the butterfly valve so not that.

also you could have a vacuum leak

How can you check for a vacuum leak?

I didn't replace TB gasket with brand new one when re-assembling, however the idle seems significantly higher to me than what a leak might cause.

[bas]

TAZ could you elaborate on cleaning the stepper motor.

When I cleaned the TB i removed the stepper motor and wiped it down abit with a cloth but not much else. I cleaned the butterfly bypass air passage though.

Also is it important to clean the area where the coolant flows into the stepper? I did not clean that pasage.

[Taz]

Unless your stepper is pretty much on its way out, what you have done should be enough. It could also be a case of the plunger having too much friction and having trouble opening and closing to let the air flow through.
How long ago since you reset the ecu? leave the car running for 30min or so, you possibly just havent given the ECU enough time to reset yet.

[bas]

I reset it then let it idle for a bit(not 30min though) and have been driving it around since.

My stepper is the old brown backing cover one too btw.

When I was checking it out the plunger was difficult to press in wards and the plastic looked very rough and old.

[silverGPX]

do you have the aircon running considering you reset the battery itll default to 24 deg max fan and ac on

[silverGPX]

do you have the aircon running considering you reset the battery itll default to 24 deg max fan and ac on

[bas]

do you have the aircon running considering you reset the battery itll default to 24 deg max fan and ac on

Nah its still that high with aircon off.

[PHIL069]

Did you re-connect the vaccum line on the side of the throttle body, under the Throttle Position Sensor?

[bas]

Did you re-connect the vaccum line on the side of the throttle body, under the Throttle Position Sensor?

I'll have to double check but i was pretty confident i reconneced everything.

[kiz]

Did you re-connect the vaccum line on the side of the throttle body, under the Throttle Position Sensor?

I'll have to double check but i was pretty confident i reconneced everything.

Yea check vacuum lines . Apparantly they can be the cause of idling at 4k revs, who woulda thought

[bas]

Ok after having a work car for a couple of days I was back in the FTO over the weekend.

The Revs still seem high but have dropped to around 1000Rpm at idle instead of 1100-1200Rpm.

I checked all the vacuum lines and everything was connected.