Fuel Pressure Regulator FCA MPROP. Maintains constant fuel pressure to the CP3 High-Pressure Injection Pump+. FCA – Fuel Control Actuator, FPR – Fuel Pressure Regulator, MPROP. THIS UNIT INSTALLS IN THE CP3 HIGH-PRESSURE PUMP. These are also called MPROP’s. The symptoms of a faulty MPROP would be rail pressure that is too high or too low. The MPROP will often fail before the pump does, getting stuck and causing the symptoms mentioned above. Pls make sure that your original OEM number is the same as this one. 2007 – 2012 Dodge 6.7L Cummins.