Idle Speed & Ignition Timing

Ignition timing and base idle speed are computer controlled and nonadjustable. Ensure idle speed and base ignition timing are set to specification. Base idle and ignition timing should be as indicated. See IDLE SPEED SPECIFICATIONS  and BASE IGNITION TIMING  tables. If idle speed is too high, correct that problem first. Check that air conditioning is off. Check for sources of undue mechanical, or electrical, loads on engine that may cause Engine Control Module (ECM) to raise idle speed. Check Throttle Position Sensor adjustment (Optima & Magentis (Canadian) only). Check for intake air leaks. Check for rich condition that ECM may be trying to compensate for. If base idle speed is okay and ignition timing is not within specifications, check camshaft position sensor, crankshaft position sensor and wiring to ECM. Also check camshaft timing.