The CP3 Diesel Injection Pump is the third generation of the Common Rail High Pressure Fuel Pump developed by Bosch. The CP3 diesel injection pump replaces the VP44 pump in most applications. What makes the CP3 and VP44 pump design revolutionary over the first generation common rail fuel systems is the extremely high pressure levels in which it delivers fuel to the combustion chamber. These pressure levels are between 4,351-23,206 psi. The Bosch VP44 and CP3 fuel systems can operate at approximately four times the level of the prior generation P7100 diesel injection pumps that had psi levels ranging in the 4,000 to 5,000 psi range. This added pressure gives the fuel injectors the ability to spray a finer mist into the combustion chamber or a more “atomized” fuel creating greater power while using less fuel.
In the Bosch CP3 pump the component that is responsible for achieving the high pressure within the common rail system is the Fuel Control Actuator solenoid valve. This valve is controlled by the pumps computer or ECP. To increase fuel flow the Fuel Control Actuator opens wider to increase fuel volume and hence increases the pressure in the system. The reverse occurs when the CP3 Fuel control Actuator is closed reducing the pressure in the system. This is based upon reading the EPC is getting from the variety of sources including the throttle control and the current pressure within the fuel system.
The CP3 fuel pump is said to be an improvement upon the VP44 fuel pump in terms of reliablity but they are still very similar in appearance. There are two potential issues with the CP3 pump that can be fixed with minimal expense and routine effort.
Problem 1 –Because the CP3 pump operates at such high psi levels it is important that all debris be removed from fuel. The fuel filter placed in most diesel vehicles in which the CP3 operates is 10 micro. We recommend a fuel filter that is 7 micro for operation with the CP3 pump. This change should increase CP3 pump life.
Problem 2 –Modern low sulpur fuel has a High Frequency Reciprocating Rig Test of greater than 520 HFRR. This is too dry to adequately lubricate the CP3 Pump. The CP3 Pump was designed for fuel mixtures that are less than 400 HFRR. In order to fully protect your CP3 pump we recommend you use a fuel additive, available through companies such as Stanadyne.
Overall Bosch fuel pump and Bosh injection systems are becoming market leaders due to the ever increasing pressure in which the Common Rail System is able to operate. |
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