- Quick diagnostic tool for ignition systems: The spark tester connects between the spark plug and spark plug wire in seconds to troubleshoot dirty spark plug connections, defective points, and bad cables or connections. - Per cylinder ignition coil test: Use this ignition spark tester to check the condition of the ignition system at each cylinder without a mechanic, enabling easy identification of weak coils or ignition faults. - Simple ignition tester design: Easily connects between the spark plug and spark plug wire for fast, on-vehicle checks. - Key benefits: Saves time by diagnosing issues on the spot; reduces guesswork and unnecessary part replacements; supports routine maintenance and quick verification after repairs. - Compatibility and performance: Designed to work with typical spark plug and wire configurations; compact plug-and-play design for easy handling and reliable feedback on ignition circuit health. - Practical use scenarios: 1) During routine maintenance on a gasoline engine to verify clean connections and wiring integrity. 2) When a vehicle shows misfire or rough idle, test each cylinder to locate the failing coil or plug/wire. 3) After replacing ignition components, perform a cylinder-by-cylinder check to confirm proper spark delivery.