Ignition Coil and Iridium Spark Plugs for Isuzu Ascender (2003-2008) 4.2L

Direct-Fit Ignition Coil and Iridium Spark Plug Kit for 2003-2008 Isuzu Ascender

What it Does: Replaces degraded factory ignition components with high-dielectric coils and fine-wire iridium plugs to eliminate cylinder misfires and restore combustion efficiency.

The Stock Ascender Ignition Degradation

The Atlas 4.2L inline-six operates in a dense engine bay prone to severe thermal cycling. Over time, the factory coil packs suffer from internal dielectric breakdown, micro-fracturing of the epoxy potting, and thermal fatigue of the copper primary and secondary windings. Combined with electrode erosion on aging spark plugs, this increases required secondary voltage, causing spark blowout, rough idle, hesitation under load, and diagnostic trouble codes P0300 through P0306.

The Engineering Solution

This 6-cylinder refresh kit pairs six heavy-duty ignition coils with six laser-welded iridium spark plugs. The coils utilize high-grade electrolytic copper windings insulated by thermally conductive epoxy to resist internal arc-over and heat soak. The iridium plugs feature a fine-wire center electrode for lower voltage demand and consistent flame kernel propagation, ensuring stable combustion under heavy throttle loads.

Technical Specifications

Compatibility

• 2003-2008 Isuzu Ascender Base, S, LS, Luxury, Limited (4.2L L6)
• Interchange Part Numbers: UF303, UF-303, 12568062, 19300921, 8-12568-062-0, 5C1392, E255, IC414, GN10114

The Isuzu Heavy-Duty Standard

Engineered to handle sustained powertrain loads, this direct-replacement ignition assembly ensures reliable cold-weather starts and consistent torque delivery whether commuting or hauling utility payloads.