Does anybody know why a throttle wouldn't close all the way?

My non-S '05 Mini is supposed to idle at 750rpm but instead idles at 1200rpm. The CVT starts from a stop very harshly with this high idle. After much searching, I've found the throttle does not close all the way. There is about a 1mm gap. There is no mechanical idle stop and I can easily open it with my fingers but it closes down leaving this 1mm gap.

It is as though the idle control motor has jumped a tooth or something. At the 1mm gap, the idle just isn't low enough.

Is there an electronic idle control?

 

Mine was idling high like yours, (however, mine is an 'S') it was caused by an electrical issue. My ground cable on the passenger side from the motor to the frame rail had gunk under it. This was causing my car to idle higher because the engine needed more voltage from the alternator since it had no connection with the battery. This probably won't be it for you but it's worth a try!

 

This might sound dumb but do you have the air conditioning on when at idle? I know my 05 R50 idles around 11-1200 with it on and 800 when off.

 

It could be a vacuum leak also......that would make the motor idle faster than normal.

No check engine light?

 

The voltage at the cpu is 14 so I don't think the low voltage idle jacking function is the problem; however, the cpu is supposed to hold it at 750 rpm regardless of A/C or other things.

Still, since the volts are good, I'm thinking it is probably the throttle or a manifold leak. It does idle slower when the A/C is off but still no lower than 800.

No there is no check engine light.

 

So you know turning on the AC creates/causes the high idle...tiny motor, decent load, motor kicks up idle...
But you still want to chase a ghost...
Go for it....

 

I suspect so. The Bentley manual says it should control the idle to 750 rpm regardless of extraneous loads. Older cars would kick the idle up high under load.

The issue is that at 1200rpm the car starts jerky with the CVT transmission and I would like to help that.

But you may be correct in that it doesn't care about computer programs and just jacks the idle anyway.

 

Did you ever find a solution to this high idle issue? My wife's '05 Cooper R52 has had a high idle of 1100-1200 rpms since we bought it 3 summers ago. Other than this "issue", the car has been great, but like you said, the CVT is jerky when starting off, probably due to this issue.

 

Sorry, no. Although sometimes it does idle a bit lower. Maybe winter time with the A/C off. I've not really paid attention. I just wait a second before driving away so the CVT tightens up first.

I suspect this is common and modern CVT's have a coded delay on the electronic gas pedal to do this invisibly.

 

I have no experience with CVT, but I would just throw in my 2 shillings. I suspect the high idle is normal due to the transmission. When the drivetrain is cold the DME will increase throttle to compensate for high drag in the transmission. There is tug of wars until the engine and transmission and its hydraulic brain are warm. I would not worry about it as long as all is well once warm up and been driven a few miles.