E-Book · Everyday Basics

Spark Plugs & Ignition Basics

Smooth idle, clean starts

What you'll be able to do: Replace plugs and diagnose ignition misfires.

Gap and torque plugs correctly, read the tips for engine health, and test coils before replacing a full set.

What's inside

• Plug types, heat ranges and gaps
• Removal without stripping threads
• Reading plug tips for diagnosis
• Coil pack and lead testing
• Misfire troubleshooting order