Development of an Electronic Fuel Injection System for a 4-Stroke Locomotive Diesel Engine

An electronic fuel injection system for a 4-stroke, 16 cylinders, V-configuration, medium speed, large bore locomotive diesel engine has been developed and successfully retrofitted on a rebuilt diesel locomotive. The engine employs a Pump-Line-Nozzle (PLN) system of fuel injection into the cylinder. Original fuel injection system used is a mechanical fuel injection pump connected to a mechanical fuel injector through a high pressure fuel line. The fuel injection pump meters the fuel delivery using a single helix machined on its plunger. The fuel injection timings are however optimized only for the rated speed and load resulting in non-optimised operation at other engine operating points. An electronic fuel injection pump having a solenoid valve for both fuel metering and injection timing along with ECU has been developed for retrofitment on rebuilt diesel locomotives. Interfacing of the ECU to the engine test cell controller has been done by developing suitable hardware and software. ECU calibration has been done and various maps of the engine have been developed. The engine was tested on the engine test bed. High pressure injector, modified fuel headers, fuel connection systems, a new high capacity fuel pump and layout of the wire harness were installed. After thorough testing and debugging, the EFI kit has been retrofitted on a rebuilt diesel locomotive and tested on load box followed by brief field trials. A savings of 4% fuel consumption over the duty cycle has been obtained. In addition there is an appreciable reduction in the smoke emissions during steady-state as well as transient operations.