High internal leakage or return flow, no injection, excessive injection and incorrect injection rate are some common problems with diesel fuel injection. The common problems with diesel fuel injection are mainly associated with two factors: quality of fuel and mechanical soundness of the injector structure. The above four problems fall into the mechanical failure category. Excess wear, abrasion and excessive buildup of deposits are some common diesel fuel injection problems falling in the category of fuel failure.
Low common-rail pressure codes and difficulty in engine starting are indicators of high internal leakage or return flow in a diesel fuel injection engine. Cracked injector and nozzle body, incorrect nozzle needle clearance, blown internal high-pressure seal and worn injector ball seat are some causes of high internal leakage.
A high balance rate is an indicator of no injection. This is caused by a bad stator, rust or debris in the injector plugging the nozzle or other mechanical problems.
Banging, poor running, excess smoke at idle and excessive temperature of exhaust gas are some indicators of excessive injection. Damaged or worn out nozzle needle, debris in control system and nozzle needle, and cracked or overheated nozzle are some causes of excessive injection.
Most of the common problems are avoidable by keeping the fuel system clean, and regularly checking for worn out components and changing them. Also, it is advisable to not use aftermarket or remanufactured components.