Denso 5319 Spark Plug

Denso Iridium Power Spark Plug 5319

Denso Iridium Power 5319 is a performance spark plug built for precise ignition and stable combustion. It uses a 0.4 mm iridium center electrode, a copper core center electrode, and a nickel ground electrode to support consistent spark delivery in demanding ignition systems.

Key Features

• Iridium tip with a 0.4 mm center electrode for focused spark initiation
• Tapercut and U-groove ground electrode tip design for efficient flame kernel exposure
• 5000 ohm resistor for noise suppression in secondary ignition systems
• 0.7 mm pre-gap for accurate factory-style setup
• 14.00 mm thread diameter, 19.00 mm reach, and flat seat design
• Heat range 31 for applications specified by the vehicle manufacturer

Product Details

The Iridium Power line is Denso’s performance-focused spark plug family, engineered around a fine-wire iridium center electrode for strong ignition response and long-term electrode stability. Part number 5319 is built with a copper core center electrode, nickel ground electrode core material, and a single ground electrode configuration to maintain reliable spark characteristics under load. This spark plug is a direct-fit style option for vehicles that call for the listed dimensions and heat range, including select Honda Civic and Toyota Corolla applications where the OE specification matches these measurements. Denso 5319 is also referenced as IW31 in interchange listings.

This part cross-references DENSO Auto Parts (e.g., IW31) for the same application.

Common Issues This Spark Plug Can Address

• Rough idle caused by worn or inconsistent spark plugs
• Hard starting from weakened ignition performance
• Misfire conditions tied to electrode wear or incorrect gap
• Reduced throttle response from inefficient combustion
• Ignition noise concerns in properly matched secondary ignition systems

Installation Notes and Tips

Verify thread diameter, reach, seat type, and heat range against the vehicle service specification before installation. Set the gap to the required value if the application calls for a different setting than the pre-gap size. Use proper torque procedures for flat-seat spark plugs and inspect ignition coils, wires, and boots during service to avoid repeat misfire concerns. For Honda Civic and Toyota Corolla maintenance, confirm the engine code and OE plug specification before replacing plugs.

Quality Assurance

Denso manufactures the Iridium Power line with fine-wire iridium electrode construction and application-specific dimensions for accurate fitment and ignition performance. Part number 5319 is built to the listed specifications for vehicles that require this plug configuration.