What Are the Most Common Signs of a Failing Injector? A failing Common Rail injector can cause significant performance issues. Watch for these key symptoms: Hard Starting or Misfiring: Difficulty starting the engine, especially when cold, or a noticeable misfire/rough idle as the cylinder with the bad injector fails to fire properly. Poor Fuel Economy and Excessive Smoke: An injector that is stuck open or leaking will dump too much fuel into the cylinder, leading to unburnt fuel (black smoke) and a sudden drop in miles per gallon. Loss of Power and Engine Knock: An injector that is clogged or not delivering enough fuel will cause that cylinder to underperform, leading to a overall loss of engine power. You might also hear a loud knocking sound from unbalanced combustion. Fuel Smell and Contaminated Oil: A leaking injector can allow fuel to drip into the crankcase, diluting your engine oil. You might smell raw fuel, and your oil level may appear to rise on the dipstick—a very serious condition that requires immediate attention. https://www.cq-longshine.com/cummins-common-rail-injector-and-pump/cummins-common-rail-fuel-injector-0445120361

How Does a Cummins Common Rail Injector Actually Work? Unlike older systems, the Common Rail system separates the generation of pressure from the injection of fuel. Here’s a simplified breakdown: High-Pressure Pump: A single, high-pressure pump (the "common rail") continuously pressurizes fuel to extremely high levels—often upwards of 30,000 PSI or more. Fuel Rail: This high-pressure fuel is stored and distributed in a tube called the fuel rail, which runs along the engine's cylinder head. The Injector's Job: Each injector is connected to this rail. When the Engine Control Module (ECM) sends a precise electrical signal, it activates a solenoid or piezoelectric actuator inside the injector. This opens a tiny valve for a nanosecond, allowing the highly pressurized fuel to atomize into an incredibly fine mist as it sprays into the combustion chamber. This precise control over the timing, duration, and pressure of each spray is what makes Common Rail engines so powerful, efficient, and clean. https://www.cq-longshine.com/cummins-common-rail-injector-and-pump/cummins-common-rail-fuel-injector-0445120361