My series 1 recently had a setup on the rollers and idle speed was ok (aprox 950RPM) for a few weeks but recently has startet to idle rather higer around the 1400rpm mark any ideas on what may be the cause of this?

 

Could be the auxiliary air device sticking open.

 

Hi thanks for the reply i thought the auxilliary air device only operated under warm up conditions? could be wrong tho! The high idle seems to be when the car has warmed up or after a spirited drive!

 

The auxiliary air device is open when cold, and progressively closes up within the first few minutes of running. Its got an internal heater, if the plug has come off or it has bad connections or anything like that it wont close up properly making it idle high when hot, same if its sticking internally.

 

Hi!

I wanted to ask, if anyone of you had a problem like this:

It's an MKIII XR3i with K-Jetronic. If I get to a traffic jam, after a few minutes the idle speed slowly gets higher and higher. Yesterday after 15 minutes it reached 4000rpm I had no better idea at the moment, I screwed the idling screw to its end in, then is decreased to 2500.

If I get out of the jam, and drive about 200-300 meters normally, then it gets back to its normal value.

Coolant temp is OK, what else can warm up, so that is causes such things?

Thanks for your help in advance!

 

I personally would say again it sounds like the auxiliary air device, either that or the over-run shut off valve. The later cars also have a idle speed control valve. Personally though i think its the auxiliary air device, the other two aren't controlled by heat.