Bonbo EN-47589 9011 Diesel Rail Fuel Injector Block Off Cap Tool Set, Fuel Pressure Test Adapter Kit for 2003-2009 Dodge Ram Cummins 5.9L, and 2001-2005 GMC Chevy Duramax 6.6L LB7 LLY, 6-PCS Set

Professional Diesel Fuel Rail Diagnostic Tool The EN-47589 9011 Fuel Rail Block Off Cap Set is designed to assist technicians in diagnosing low fuel rail pressure conditions, injector return flow problems, hard starting, rough running, and injector-related engine performance issues on Cummins and Duramax diesel engines. Quickly Identify Faulty Injectors When fuel rail pressure is too low to start the engine, a faulty injector may be returning excessive fuel back to the tank. By removing the injection line from an individual cylinder and installing the block off cap in its place, you can isolate injector circuits and determine which cylinder is causing the pressure loss. Compatible Vehicle Applications For 2003-2009 Ram 2500 and 3500 trucks equipped with 5.9L Cummins ISB diesel engines. Also fits 2001-2005 Chevy and GMC 2500HD/3500HD models equipped with 6.6L Duramax LB7 and LLY diesel engines, including GMC TopKick C4, C5 applications and Hummer H1 Alpha. Built for Professional Use Constructed from premium steel and copper materials for long-lasting durability and dependable sealing performance. Precision machining ensures accurate fitment and reliable operation during fuel system diagnostic procedures. Ideal for Multiple Diagnostic Scenarios Suitable for diagnosing injector return flow issues, excessive fuel leakage, fuel rail pressure loss, injector imbalance, engine knocking, rough idle, and hard-start conditions. Multiple caps allow testing of several injector circuits when required. Package Includes 6 × EN-47589 9011 Fuel Rail Block Off Caps

• 【Application】 Engineered to precise OEM standards. It is fully compatible with 2003-2009 Dodge Ram 2500/3500 Cummins 5.9L ISB Diesel, and fits 2001-2005 GMC/Chevy 2500/3500 Duramax 6.6L (LB7 / LLY) engines, including Medium Duty GMC Topkick C4/C5 and Hummer H1 Alpha.
• 【Diagnose Fuel Pressure Problems Quickly】 EN-47589 Fuel Rail Block Off Cap Tool is designed to isolate faulty diesel injectors during fuel pressure diagnostics. By blocking off individual injector ports on the fuel rail, technicians can quickly identify leaking injectors, excessive return flow, hard-start conditions, and low rail pressure issues.
• 【Identify Faulty Injectors with Confidence】 When a defective injector returns excessive fuel to the tank, rail pressure may drop below starting requirements. This block off cap allows you to isolate each injector circuit and determine which cylinder is causing pressure loss, injector imbalance, rough idle, or engine knocking.
• 【Heavy-Duty Steel & Copper Construction】 Manufactured from premium high-strength steel and copper materials for excellent durability, wear resistance, and corrosion protection. Precision-machined threads provide a secure fit and reliable sealing during diagnostic testing.
• 【6-Piece Professional Diagnostic Set】 Includes six 9011 fuel rail block off caps for testing multiple cylinders as needed. Highly advantageous when multiple injectors are leaking simultaneously. If you are not satisfied with our products, you can request a refund within 30 days. Backed by a 12-month warranty for your peace of mind.