High idle speed

528iE12 · Post by **528iE12** » Tue Mar 18, 2014 3:14 pm

My 528i has too high idle speed, when cold about 2300rpm, hot about 1300rpm. I have adjusted the ignition, co and the throttle damper. before this it was about 1500 when the engine was hot.

Mike W. · Post by **Mike W.** » Tue Mar 18, 2014 10:01 pm

A picture would help given that it's probably something we didn't exactly get here, but I'll give it a try. False air. It's probably getting too much air from somewhere. There is the idle adjustment screw in the throttle body. That obviously lets more air in. There is a "test" adjustment screw up top on the linkage, that should have a gap and not affect things. Does the throttle linkage move freely, especially at closing? Vacuum hoses all good? If you have a dual diaphragm distributor does the retard side work at idle? Are the distributor vacuum hoses connected correctly?

Look at those things and let me know if it's still a problem.