Tried searching, but the Search is acting up. Anyway, my car (87 turbo) recently started having idle problems. After driving at over 50 mph for at least 5 minutes (ie highway driving) and letting off the throttle, the idle will dip to about 500 rpms and the car will want to die out. After a few more minutes of regular driving (under 50 mph) the idle will eventually settle back to 900 (where I have it set). If I drive fast again, then slow back down, the idle will dip back to 500-ish. Any ideas???