Reasons for Diesel Engine Fuel Injector Not Spraying Fuel
1 Answers
Injector failures are primarily caused by needle valve issues due to contaminants in the diesel engine. The main reason is that the injector tip in the combustion chamber is exposed to prolonged high-temperature and high-pressure conditions. Below are the causes and solutions: 1. Poor injector atomization: When injection pressure is too low, nozzle holes are worn with carbon deposits, or spring end faces are worn with reduced tension, the injector may open prematurely and close late, resulting in poor fuel atomization. For single-cylinder diesel engines, this prevents operation; for multi-cylinder engines, it causes power loss, black exhaust smoke, and abnormal engine noise. Additionally, oversized diesel droplets that fail to combust completely may flow down cylinder walls into the oil pan, raising oil levels, reducing viscosity, worsening lubrication, and potentially causing bearing seizure or cylinder scoring. Solution: Disassemble, clean, inspect, and recalibrate the injector. 2. Damaged injector return line: When needle valve pairs are severely worn or the needle valve body fits loosely with the injector housing, return fuel flow increases significantly (up to 0.1-0.3kg/h). A damaged or missing return line wastes this fuel. The return line must be intact and sealed to allow fuel to flow back to the tank. If connected to the diesel filter, its end should have a check valve to prevent backflow.
