lemon-mirror:
Home >> Chevrolet >> 1990 >> APV >> Repair and Diagnosis >> Engine Performance >> Engine Controls - Adjustments >> V8 Ignition Timing >> All Models (Except Diesel)

All Models (Except Diesel)

  1. Set parking brake, block drive wheels and place transmission in Neutral or Park. Warm engine to normal operating temperature. Turn A/C off (if equipped). Ensure SERVICE ENGINE SOON light is off.
  2. Disconnect Tan/Black wire EST by-pass connector located behind electrical junction box cover or near distributor. DO NOT  disconnect 4-wire connector at distributor.
  3. Connect timing light to No. 1 spark plug wire. Check timing and adjust if necessary. See V8 IGNITION TIMING SPECIFICATIONS  table. Reconnect EST by-pass connector and clear ECM trouble code.
V8 IGNITION TIMING SPECIFICATIONS (Degrees BTDC @ RPM)

Application Man. Trans. Auto. Trans.
5.0L (VIN H) 0 @ Idle 0 @ Idle
5.7L (VIN K) 0 @ Idle 0 @ Idle
7.4L (VIN N) 4 @ Idle 4 @ Idle