Connect tachometer to check connector. Check connector is located on right rear corner of engine compartment, near automatic transmission dipstick. Remove No. 1 ignition coil. Connect No. 1 ignition coil and No. 1 spark plug with a high tension wire. Connect timing light to high tension wire. Start and warm engine to normal operating temperature (needle is in middle of coolant gauge).
Operate engine at 2000 RPM for 2 minutes. Perform self-diagnostic procedure, and check for smooth engine operation. See G - TESTS W/ CODES article in the ENGINE PERFORMANCE Section. Increase engine speed to 2000 RPM, 2 or 3 times, then allow engine to return to idle.
Check ignition timing. See IGNITION TIMING table. If ignition timing is incorrect, loosen crank angle sensor mounting bolts. Adjust timing by turning crank angle sensor. With ignition timing correctly set, check idle speed and mixture. See IDLE SPEED & MIXTURE. Reinstall removed components.

IGNITION TIMING (Degrees BTDC @ RPM) ⁽¹⁾

Application

Specification

G20

13-17 @ 700-800

M30

13-17 @ 750-850

Q45

13-17 @ 600-700

⁽¹⁾	With transmission in Neutral and no load on engine.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

V8 Ignition Timing: Q45