Series 40E Troubleshooting – Section 3.1 Injection Control Pressure System Operation

Section 3.1
Injection Control Pressure System Operation

The Injection Control Pressure system provides the necessary energy to hydraulically actuate the HEUI injector. Engine oil is the hydraulic fluid used by this system for this purpose.‪

Oil is drawn from the oil pan through the pick-up tube by the engine oil lubrication pump. The lubrication pump is a gerotor type pump driven by the crankshaft. Filtered oil is fed through passages in the front cover to the oil reservoir which is an integral part of the front cover. See Figure
“Injection Control Pressure System”


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1. Oil Reservoir‪

5. Oil Manifold‪

2. Hose‪

6. High Pressure Oil Pump‪

3. Injection Control Pressure Sensor‪

7. Injector Pressure Regulator Valve‪

4. Injectors‪

Figure 1. Injection Control Pressure System

The reservoir makes available a constant supply of oil to a high pressure hydraulic pump mounted to the front cover. The high pressure pump is a gear driven swash plate pump. High pressure oil is delivered by the high pressure pump to the high pressure oil supply manifold and into the oil passages machined into the cylinder head.‪

This high pressure oil is utilized by the HEUI injector when the solenoid is energized to pressurize and atomize the fuel into the combustion chamber. After injection is completed, the solenoid is de-energized and the oil inside the injector is vented through the top portion of the injector, splashed on the valve train and allowed to drain back into the oil pan.‪

Injection control pressure is governed by the Electronic Control Module (ECM) depending upon the operating conditions and the driver’s demand for power. The injection pressure regulator (IPR) is utilized by the ECM for this purpose.‪

The IPR is a pressure regulator valve that is electrically controlled by the ECM to control the pressure of the entire injection control pressure system. The IPR valve is mounted on the high pressure pump and achieves injection control pressure regulation by dumping excess oil into the front cover and back to the oil pan.‪

The injection control pressure sensor provides pressure information in the form of an analog voltage signal to the ECM at any time.‪

The injection control pressure ranges from 3.4 to 20 kPa (500 to 3000 lb/in.2
), depending on the engine family.‪

Series 40E Troubleshooting Manual – 6SE241
Generated on 10-13-2008