Autool SPT301 | Spark Plug Tester
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Warranty directly via AsTools
Warranty directly via AsTools
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2 years warranty on all products
2 years warranty on all products
All our products come with a 2-year factory warranty. This ensures you long-lasting quality and service.
Easy returns
Easy returns
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Professional customer service
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The Autool SPT301 spark plug tester is designed for visual inspection and performance analysis of components within the ignition system. This diagnostic device enables technicians to assess the quality, stability, and color of the ignition spark under simulated engine load. The tester is mainly used for targeted diagnosis of ignition problems in 12V gasoline engines, where misfires, weak sparks, or internal breakdowns can be quickly identified without the parts needing to remain installed in the vehicle.
During the diagnostic process, the tester itself generates the required high voltage, taking over the function of the coil, allowing the spark plug to be mounted directly in the test station. Although the physical electrode gap on the spark plug itself is adjusted and not on the device, the tester controls the spark intensity by continuously simulating engine speed between 200 and 9000 RPM. The device is equipped with height-adjustable threaded connections to support different shaft lengths. A closed safety cover over the test setup is required to activate the circuit, ensuring safe visual inspection of the spark plug spark without risk of contact with high voltage.
ADVANTAGES
ATTENTION POINTS
Applications and functionalities
The Autool SPT301 offers specific test functions for evaluating spark plugs outside the combustion chamber (bench-testing).
- RPM Simulation: Generating a high-frequency operating voltage to simulate engine speeds from 200 to 9000 RPM, allowing visual assessment of the spark plug's behavior under varying loads and high speeds.
- Comparative spark analysis: Simultaneous operation of three test ports. One port is for a new reference spark plug, while the other two ports are used for the spark plugs being tested, allowing direct observation of performance differences.
- Visual spark diagnosis: Assessment of spark color, intensity, and stability to detect breakdown, internal insulation defects, abnormal spark paths, or severe electrode wear.
Special features and capabilities
This model is equipped with hardware modifications to increase compatibility and ensure safety during testing.
- Height-adjustable test ports: The threaded connections can be mechanically adjusted up to 8 millimeters in height. This allows a proper ground connection for spark plugs with a longer shaft or different thread position.
- Integrated high-voltage protection: The device is equipped with a transparent safety cover. The high-voltage circuit is secured so that the test cycle can only start when the cover is fully closed, preventing electric shock.
- Digital control panel: An LED display shows the set RPM value in real time. The push buttons allow the test frequency to be increased or decreased stepwise for precise control.
Compatible vehicles and ignition systems
The tester is designed for universal use with components from standard 12-volt ignition systems.
- Vehicle category: Passenger cars, light commercial vehicles, motorcycles, and other gasoline combustion engines.
- Ignition system: 12V conventional and electronic ignition systems with loose spark plugs (including extended models from BMW, VAG, and Audi).
- Diagnostic application: Checking spark quality and physical breakdown of disassembled spark plugs on the workbench.
Package Contents
- 1x Autool SPT301 Spark Plug Tester
- 1x Power Adapter (110V/220V to 12V DC)
- 1x User manual
Technical specifications
| Specification | Description |
|---|---|
| Product brand | Autool |
| Product model | SPT301 |
| Simulated speed (RPM) | 200 - 9000 RPM (adjustable) |
| Number of test ports | 3 (1x reference, 2x test) |
| Adjustable test height | 0 - 8 mm |
| Adapter input voltage | AC 110V / 220V ±10% |
| Device operating voltage | DC 12V ±1A |
| Operating temperature | 0°C to 45°C |
| Relative humidity | < 85% |
| Dimensions (L x W x H) | 200 x 118 x 118 mm |
| Weight | 500 grams |










