806 irratic idle.

[pugbus96]

Hi There,

My 1996 P Reg 2 .0 litre petrol has developed an idling problem ,it feels like the idle valve is partially sticking ,if it has one , Starting from cold feels like it has a fast idle and stays that way for a while then settles to a normal idle ,get to work ,no drama . If i start it again later on the revs climb to two thousand or so and it won't come down for a while . I've also noticed that sometimes the throttle will snap shut on the over run and the vehicle jerks ,and other times the idle will come down gently as it should . I've cleaned all the breather pipes and I've cleaned what looks like a throttle stop valve ? as both these items looked a bit worse for wear ,not having any workshop manuals on these vehicles makes it a bit more difficult . I've just done the o/s cv joint with no problems and other than the problem I've just described it's a good all rounder .Thanks in advance .

[jozzyman]

Hi i had irratic idle on my audi i cleaned throttle body with a good carb cleaner all sorted its also worth checking pipes for splits hope this helps mate

[pugbus96]

Originally Posted by jozzyman

Hi i had erratic idle on my audi i cleaned throttle body with a good carb cleaner all sorted its also worth checking pipes for splits hope this helps mate

Hi Ya , I did the same and it certainly helped ,but the problem persists, many thanks for your input.

[davidireland]

Remove idle control stepper motor and clean the housing it fits into. A can of carb cleaner will do the trick. Make sure ignition is off before removing it. There should be two torx 20 studs holding it on.

[pugbus96]

Originally Posted by davidireland

Remove idle control stepper motor and clean the housing it fits into. A can of carb cleaner will do the trick. Make sure ignition is off before removing it. There should be two torx 20 studs holding it on.

Sorry to be vague but is it black and round and to the left of the butter fly /throttle housing as you look in the engine bay ,and if it is then i have removed it and cleaned it and the hole it fits in and they were both filthy but the problem is still there . I have to say that before i cleaned these items i had a violent jerking issue that disappeared when i cleaned them but the idle issue is driving me mad .I have another idle control valve which i may try ,time permitting.

[davidireland]

Yes black and round. It is made by Magnetti Marelli. When you take it out take a look at the seat of the little plundger. Around the edge of it you will see maybe a shiny bit and then a sooty bit. The shiny bit is where it is seating correctly and the black sooty bit is where it is leaking air. Clean all including the throttle body.

[pugbus96]

Originally Posted by davidireland

Yes black and round. It is made by Magnetti Marelli. When you take it out take a look at the seat of the little plundger. Around the edge of it you will see maybe a shiny bit and then a sooty bit. The shiny bit is where it is seating correctly and the black sooty bit is where it is leaking air. Clean all including the throttle body.

Thanks very much Dave ,I have had this out and cleaned it but maybe there is a tiny spec of dirt stopping it working properly ,i have another one and i'll try this as well .It a shame Haynes or someone doesn't do manuals for these vehicles ,they are popular enough ,it would make identifying items a load easier ,I'll let you know how i get on sometime in the week. Many thanks

[pugbus96]

Originally Posted by davidireland

Yes black and round. It is made by Magnetti Marelli. When you take it out take a look at the seat of the little plundger. Around the edge of it you will see maybe a shiny bit and then a sooty bit. The shiny bit is where it is seating correctly and the black sooty bit is where it is leaking air. Clean all including the throttle body.

Hi Dave , Had a clean up today of said item and guess what ,the jobs a good en. I think there may have been a tiny bit of debris still lodged in there as the vehicle is so much better to drive and it seems smoother too ,thanks for your input and knowledge. see you on here sometime soon. Regards Chris.

[pugbus96]

Hi, well it lasted a few days i guess ,i even changed the stepper motor but the fast idle is back with a vengeance .Is there a throttle position sensor or maybe a heat sensor playing about? Does this model have a diagnostic plug as i don't have planet ,and what is the sensor in the throttle body ,does this have anything to do with it maybe ? Is it worth taking the throttle body off and having a good clean out ,I've checked all the basic stuff such as sticking throttle cable and linkage etc ,no probs there and no air leaks as far as i can see.

[davidireland]

You need to retrain the stepper motor.
Ign off, ign on for ten seconds, ign off for ten seconds. Do this a few times and it should learn.