bosch common rail injector repair manual

It routes diesel that is designed to leak out of the metering unit (when it’s in the closed position) away from the plungers in the pump and back to the gear pump inlet. The zero delivery throttle (E) exists for instances in which no additional fuel is required in the rail.

The metering unit, also known as the MPROP, FCA, or fuel pressure regulator, regulates the maximum flow rate the CP3 delivers to the rail. The overflow valve returns fuel to the gear pump inlet, provides lubrication for the pump, and keeps pressure in front of the metering unit (D) constant. The maximum flow rate of the gear pump is limited by the calibrated suction throttle (B) to avoid an overload scenario at the overflow valve (C). The gear pump’s purpose is to feed the high-pressure pump.

First, low-pressure fuel enters the gear pump (A). This diagram (which shows the low-pressure fuel circuit on the right side of the pump) is similar to what you’d see in a Bosch CP3.3 NH pump, which is the model used on an LBZ Duramax. Stroker pumps), we first have to understand the CP3 pump’s functionality.

Low-Pressure Circuit In order to talk about the modified injection pumps available in the aftermarket, which feature increased displacement (i.e. The fact that the CP3 came from Bosch’s heavy-duty line of injection pumps also speaks to its great reliability, as it was designed to play a vital role in million-mile engines. The CP3 injection pump’s sole job is to create and regulate high-pressure fuel (it’s not timed with the engine’s crankshaft and camshaft). Unlike previous (pre-common-rail) injection pumps, it has fewer tasks to perform. In the case of the ’01-to-’10 Duramax and ’03-to-present Cummins, the heart of the common-rail system has been the Bosch CP3. The icing on the cake is that these cleaner-burning engines make much more power than their predecessors. Use of the common-rail system has also facilitated multiple injection events (making diesels quieter).

Over the last decade, it has allowed engine builders to run higher injection pressures (as much as 29,000 psi in the new LML Duramax and 6.7L Power Stroke) in order to increase efficiency, while greatly reducing emissions. High-pressure common-rail injection technology has revolutionized the diesel industry. › Bosch Cp3 Fuel Injection Pump Service Manual ▼

Bosch common rail injector repair manual