Lisle InLine Spark Tester w/Coil On Plug Wire - Quick Spark Check

In this review of the Lisle InLine Spark Tester w/Coil On Plug Wire, the bottom line is simple: this is a practical, no-nonsense tool for anyone who needs a quick visual confirmation of ignition spark. It connects between the spark plug and plug wire and flashes a mirror image of the ignition spark with the engine running, so technicians and home mechanics can rapidly isolate ignition problems without guessing. The included short double-ended lead and a 7' extension for recessed coil-on-plug applications make it more versatile than a single-boot tester.

Key Features

• Inline connection: Connects directly between the spark plug and plug wire so the tester shows a real-time image of the ignition spark while the engine runs.
• Double-ended short wire: The short lead offers both a straight boot and a 90-degree boot on the same tool, making it compatible with different plug orientations.
• 7' extension plug wire: The extra extension reaches recessed coil-on-plug locations and tight engine bays for easier access.
• Visual spark feedback: The tool flashes a mirror image of the spark so users can confirm whether an ignition event is occurring without using improvised methods.
• All ignition systems: Designed to quickly diagnose problems across traditional and modern ignition setups, saving diagnostic time.

Who It's For

This tester is aimed at automotive DIYers, small engine owners, and professional technicians who need a straightforward way to verify spark without specialized diagnostic gear. It is especially useful for anyone who prefers a simple visual check that is quicker than removing plugs or using a screwdriver to test for spark.

Those who should look elsewhere include users demanding advanced electronic diagnostics, data logging, or precise timing adjustment tools - this tester provides clear visual confirmation of spark but does not record or quantify ignition parameters.

Pros & Cons

Pros

• Works well as a direct visual check of ignition spark, reducing guesswork during troubleshooting.
• Quality build and clear visibility make it effective in a range of conditions, particularly in well-lit areas.
• Versatile wiring with both straight and 90-degree boots plus a 7' extension improves access to hard-to-reach plugs and coil-on-plug units.

Cons

• Provides visual feedback only and does not offer electronic measurements or data logging for deeper diagnostics.

Specifications

Product	Inline spark tester with coil-on-plug wire
Connection	Sits between spark plug and plug wire
Short wire	Double ended: straight boot and 90-degree boot
Extension	7' extension plug wire for recessed coil-on-plug
Use	Diagnose all ignition systems with engine running
Included	Inline tester with short double-ended lead and 7' extension

Our Verdict

The Lisle InLine Spark Tester w/Coil On Plug Wire is a practical, value-focused tool for anyone who needs fast, reliable visual confirmation of spark. It is well suited to home mechanics and pros who want to speed up ignition checks without fancy electronics, and the double-ended boot plus 7' extension make it versatile for many engines.

Frequently Asked Questions

Can this tester be used while the engine is running?
Yes. The tool is designed to flash a mirror image of the ignition spark with the engine running so you can observe spark behavior in real time.

Will the 7' extension reach recessed coil-on-plug designs?
Yes. The included 7' extension plug wire specifically helps reach recessed or hard-to-access coil-on-plug locations.

Is this suitable for all ignition systems?
The tester is intended to quickly diagnose problems across common ignition systems, but it provides visual confirmation only and not electronic measurements.