Feedback System
Ensure ignition timing and idle speed are adjusted. See ADJUSTMENTS article in the ENGINE PERFORMANCE section. Warm engine to operating temperature. Run engine unloaded at 2000 RPM for 2 minutes. Enter self-diagnostic Mode II. See appropriate G - TESTS W/ CODES article in the ENGINE PERFORMANCE section below. If Red LED on ECM (or CHECK ENGINE light) does not flash at least 5 times in a 10-second period, perform IDLE MIXTURE adjustment procedure in ADJUSTMENTS article in the ENGINE PERFORMANCE section.