IST1 - Check Idle Speed

^ Start the engine and run until at normal operating temperature.

^ Engine at idle.

^ All electrical loads OFF.

^ Connect Rotunda 88 Digital Multimeter 105-00053, or equivalent as a tachometer.

Data Link Connector:

^ Ground the Self Test Input (STI) connector.

^ Check idle speed:

ATX and MTX 750 ±50 rpm

^ Is idle speed within specifications?

YES -- Go to IST2. IST2 - Check Base Timing

NO -- Adjust idle speed.