1987 635CSi idle problem
 

I recently acquired a 87 635csi in California. When I drove it home to Wyoming I expericienced no problems at all on a 1000 mile trek. After driving it here at 6200 feet in elevation for a day - no problems. However, today I started it up and the idle jumps from 100rpm-2000rpm and back repeatedly. I opened the hood, jingled the throttle and the idle went back to normal. After leaving work the same thing happened at start up, jiggled under the hood again and nothing - drove it home (10 miles) and the idle kept jumping. What should I do? where do I start? injectors, stuck idle cable? please help.

http://members.roadfly.com/kcroncarter/bmwetm214.jpg

In figure 3 there is the idle actuator.

Try cleaning the slider with a spray of wd40.

If the fails to correct it you can replace it and Pelican Guys will help there.

You can make a temporary correction by drilling a 1/4 inch hole in a penney. Place the penney in the intake to the idle valve and it will restrict the max RPM to the 1/4 inch hole and solve the issue.

Yours is not covered exactly but the issues and corrections are the same. Have you met Sam yet?
http://www.mesaperformance.com/faqs/idle.html

Later,
http://members.roadfly.com/kcroncarter/me.GIF