Feedback System

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