High idle

[Campo di Classico]

I started my 3.0csi last night and the idle jumped up very high and I couldn't get it no normalize. I took it for a quick spin to see if it needed to cough out a furball but that didn't work :/ any ideas if it's a bad part or adjustment?

Thank tou for your education and experience Ken

 

[Arde]

The latest guidance I got was that a vacuum leak would produce a systematically high idle, while a bad O2 sensor would produce erratic or hunting idle. Finally, a bad Idle Control Valve caused high idle for me on the E24 that would go lower upon a light tap to the accelerator. Again, the above is second hand hearsay and idle talk.

 

[bengal taiga]

My vote is for a vacuum leak. On your djet there are many possibilities. The easiest to check might include a loose vacuum hose that connects “slips” on to the distributor retard mechanism. Auxiliary air intake valve that fails to close fully is also a likely candidate as is the hose from the valve to the manifold. While unlikely, there is a hose from the manifold that feeds the brake booster and then there is the booster itself. An unusual “hiss” may be a good clue.

An alternative theory regarding a "high" idle might involve the late Mr. Marley, but there is nothing referenced in the shop manual index.

For starters >>

https://e9coupe.com/forum/threads/d-jet-cold-idle-speed-aux-air-valve.27847/
https://e9coupe.com/forum/threads/aux-air-valve.28557/

 

[Campo di Classico]

Problem solved! In searching for a vacuum leak, I discovered the throttle linkage wasn't returning. Lubed it all up and we're good to go. Thanks everyone!