Idle speed hanging @ 1'8000 rpm

[fender]

I have a 95 petrol inj Espace. When warm the idle speed stick's at 1,800 rpm. If I blip the acc pedle it then drop's to normal rpm.
 When cold it is not effected, only when a warm engine.
  If I drop to idle from 2,000 rpm the idle is o.k, if I drop to idle from 1,800 it just stay's there.
  I can also reduce the rev's by letting the clutch out a little whilst in gear.
  Possible air leak or dreaded idle speed valve?
  Any advice would be most welcolme.
Regards Karl

[Anders Dinsen]

This is surely the idle speed valve - get it out and clean it inside first, before replacing it. Sometimes that can do it, but not always. If it doesn't help, you will need a new one.

I have put some info on this on this page: http://dinsen.net/espace/teknik/j11-j63/fuelinjection (scroll down to "Idle speed valve")

[fender]

Thank's Anders, What do I use to clean it out? Tha valve seem's to move freely, but maybe it's sticking on a light throttle.
Regards Karl

[Anders Dinsen]

Thank's Anders, What do I use to clean it out? Tha valve seem's to move freely, but maybe it's sticking on a light throttle.
Regards Karl

WD40 is usually good enough, but if it moves absolutely freely, then that's probably not the cause... Yes, it could be sticking on light throttle, but I don't think so if it moves okay in the full band. Sometimes you can feel dirt moving with the valve when you put your little finger in to move it, then it could be sticking. Have you tried applying power with a 9V battery to the terminals to see if it closes and opens?

Have you tried running the car again after this, and the problem still persists?

Now that we kind of have eliminated the idle valve, I'm think it could also be your throttle potentiometer (or actually only a double switch) that has come loose. It sits on the backside of the throttle body on top of the manifold and has a three wire connector identical to that of the idle valve (don't swap them!)

- Anders

[fender]

Anders, Thank's again for pointing me in other possible solution's. I will double check both of you'r suggestion's once I can get into the garage (du to windy weather).
 Is the potentiometer easy to set? and how would this be done?
 Sorry if I'm being too persistant, but I do value the information.
Regards Karl

[Anders Dinsen]

Anders, Thank's again for pointing me in other possible solution's. I will double check both of you'r suggestion's once I can get into the garage (du to windy weather).
 Is the potentiometer easy to set? and how would this be done?
 Sorry if I'm being too persistant, but I do value the information.
Regards Karl

No problem, don't be sorry!

The potentiometer isn't difficult to set as you can hear when it is activted. It contains two switches - one is supposed to be activated when the throttle is released (idle), then other when it's fully open. The adjustment happens by rotating the unit which is possible if you loosen the two screws. Maybe you can get your head in there to look, otherwise you need a mirror

But on second thought, I'm afraid I'm wrong with that... the thing is: If the potentiometer was set incorrectly, it would not activate the idle switch, and the idle would be too low or the engine would be close to stalling. From your description it really sounds like the idle speed valve sticking and everytime you do something that makes the computer move it, it comes free and works.

And they are known to give problems.

- Anders

[fender]

Thanks Anders, I'll try the WD40 and rock it to and fro a few time's with my stubby finger (again). I think because of the closeness to the engine, the WD40 may evaporate rather quickly.
Regards Karl