Series 4000 Fuel System Technician Guide INTRODUCTION The purpose of a properly designed fuel system is to provide clean fuel, free from air, water or dirt, and to deliver fuel to the engine at correct amounts for good combustion to provide optimum power, fuel economy and emissions compliance. A unique feature of the Series 4000 is the common rail fuel injection system. This system relies on a single high-pressure fuel pump that provides a continuous supply of fuel, at injection pressure, to all of the injectors at all times. This common rail fuel system does not require cam driven unit injectors or injection pumps with separate cam driven plungers to make fuel pressure for each injector.
The unit injectors in the Series 4000 common rail fuel system do not make fuel pressure. DDECIV Electronics alone control injector timing, the amount of fuel and atomization of fuel being supplied from the high-pressure rails. The Common Rail Fuel System provides the Series 4000 with the most advanced fuel system technology available today. The Common Rail Fuel System consists of many unusual components not found in other diesel fuel systems. Therefore, the Fuel System Technician Guide is intended to help better understand the Common Rail Fuel System operation and components as well as provide failure analysis to properly maintain this unique system for maximum performance.
This manual is applicable to all engine sizes and product applications of the Series 4000 and is intended to be expanded upon, as additional information becomes available. It is also a good place for the technician to add helpful notes on the fuel system for future reference. SAFETY Safety is always our first concern. To guard against safety mishaps while working on the common rail fuel system, there are a couple of areas of caution to be noted: The common rail fuel system operates at pressures up to 19.6 KPSI (19,000 PSI). Fuel at this pressure can be very hazardous causing bodily injury or fire if proper repair procedures are not followed.
Fuel under high pressure creates a very fine spray, which can penetrate the skin or cut! Appropriate safety equipment should be worn to prevent injury. NEVER ATTEMPT REPAIRS OF HIGH- PRESSURE FUEL LEAKS WHILE AN ENGINE IS IN OPERATION! Under certain conditions the high-pressure fuel lines from the high-pressure fuel rail to the injectors can become heated from combustion gases. Care should be taken to prevent the possibility of burns from excessive contact with theses fuel lines. Page 1