With HPOP failures (very similar to leaks in the High-Pressure oil system), you will see a lack of power with high IPR numbers and ICP less than desired. From what I understand, the only sure way to identify a bad HPOP is to remove the pump and remove the cover and rotating assembly to inspect it.Apr 11, 2020
What does an HPOP do?
The HPOP provides oil volume for the fuel injectors to use and its accompanying injection pressure regulator (IPR), which controls HPOP outlet pressure and is located in the HPOP cover, pressurizes this oil as high as 3,600 psi in stock form.Mar 12, 2021