Choke??? KE systems don't have a choke in the conventional sense like a carburetor. The idle speed and mixture, cold or hot, is controlled by the electonics via the idle speed control valve and electo-hydraulic actuator.
The first thing I would check is the throttle position switch and linkage microswitch, and the linkage, too. After this the idle control valve and then the air flow valve potentiometer.
There have been many recent threads on these issues, so a search should provide a wealth of information. The KE system on the all late eighties engines - four, six, or eight cylinder are the same technology, have the same components, and the same problems, many of which are simple to correct.