{"product_id":"ignition-coil-and-iridium-spark-plugs-for-jaguar-xjr-1999-2003-4-0l","title":"Ignition Coil and Iridium Spark Plugs for Jaguar XJR (1999-2003) 4.0L","description":"\u003ch2\u003eDirect-Fit Ignition Coil and Iridium Spark Plug Kit for 1999-2003 Jaguar XJR\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003ePrimary Function:\u003c\/strong\u003e Restores factory spark energy, resolves high-load misfires, and stabilizes idle across all 8 cylinders on supercharged 4.0L AJ-V8 engines.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock XJR Ignition Breakdown\u003c\/h3\u003e\n\u003cp\u003eThe supercharged AJ26S\/AJ27S generates substantial cylinder head heat soak within the cramped X308 engine bay. Over time, OEM coil boots degrade, causing dielectric breakdown, micro-arcing against the plug wells, and secondary winding insulation failure under forced-induction cylinder pressures. Worn factory plugs also develop excessive electrode gaps, driving up coil primary resistance and triggering P0300-P0308 DTC misfire codes, rough idle, and unburned fuel entering the catalytic converters.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThis matched ignition service kit provides eight heavy-duty coil-on-plug assemblies wound with high-conductivity copper wire and encapsulated in high-dielectric epoxy to resist thermal fatigue. Paired with fine-wire iridium spark plugs, this setup lowers required ignition voltage, improves flame kernel development under positive boost pressure, and resists electrode erosion. Factory-matched blade terminals and OEM plug geometry ensure exact plug-and-play installation without wiring modifications.\u003c\/p\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable width=\"100%\" style=\"border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px;\"\u003e\n  \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003eFitment\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003e1999-2003 Jaguar XJR\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003eEngine \/ Chassis\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003e4.0L Supercharged AJ-V8 (AJ27S) \/ X308\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003eStock Output\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003e370 hp \/ 387 lb-ft (Approx)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003ePart Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003eUF415, LNE1510AB, XW9312029AB, C1323, 5C1180\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1999 Jaguar XJR 4.0L V8 Supercharged (X308)\u003c\/li\u003e\n  \u003cli\u003e2000 Jaguar XJR 4.0L V8 Supercharged (X308)\u003c\/li\u003e\n  \u003cli\u003e2001 Jaguar XJR 4.0L V8 Supercharged (X308)\u003c\/li\u003e\n  \u003cli\u003e2002 Jaguar XJR 4.0L V8 Supercharged (X308)\u003c\/li\u003e\n  \u003cli\u003e2003 Jaguar XJR 4.0L V8 Supercharged (X308)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eThe Jaguar Standard\u003c\/h3\u003e\n\u003cp\u003ePrecision supercharged European powertrains require consistent secondary coil voltage to maintain tight closed-loop fuel trims. This complete refresh delivers factory-spec resistance values to prevent false misfire flags and maintain smooth power delivery without CEL complications.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":50447748071672,"sku":"DS-EERZAMX2A","price":175.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/ignition-coil-and-iridium-spark-plugs-for-jaguar-xjr-1999-2003-4-0l-1.jpg?v=1788622960","url":"https:\/\/performancechiptuning.com\/products\/ignition-coil-and-iridium-spark-plugs-for-jaguar-xjr-1999-2003-4-0l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}