idle problem

["checksix3" <jetjock11@xxxx>]

...I have yet to see the proper way to set up the idle speed system 
(the Bosch recommended method) in any post or archive. As long as you 
have no air leaks and your CO is set closely this will solve all idle 
hunting...period. Some airflow trough the throttle body and metering 
plate is required for the system to work properly. This is obvious if 
the conductance of the system is measured. 

Opening the loop by disconnecting the engine speed input variable 
(pin 12) on the idle ECU while keeping the idle switch closed and 
forcing the CIS motor to it's basic default position is the key to 
proper setup of the CIS system. (This is also a convienent method of 
setting manual idle if you prefer not to use the CIS, although the 
switch only needs to be kept closed during setup.) You should also 
test the components before you attempt setup to be sure they're 
working.

I also point out an open circuit or high value in the CIS warm up 
thermistor will cause a default idle speed of appx 2000 rpm. Be sure 
this circuit is not open. Jumper it (or measure it) at the ECU if you 
have a doubt, zero ohms or any value below appx 10K will ensure the 
ECU setpoint is 775 rpm.

Fwiw, my car idles perfectly, hot or cold, from the moment it's 
started.