ERIKC DLLA147P788 denso common rail injector DLLA 147 P 788 diesel fuel injector nozzle DLLA 147P788 for 095000-0630

FAQ: What should I do if the high pressure pump fails? Actual rail pressure is too high and fuel injection is below the threshold

ERIKC Answer: Symptom: The system pressure is too high. Generally, the system will have limited engine speed or torque after starting.

Possible Causes:

1) The poor oil return of the oil pump causes too much fuel to enter the oil pump plunger, resulting in excessive rail pressure; 2) The oil pump fuel metering unit stuck in the normally open or open position, resulting in high rail pressure; 3) oil pump overflow Flow valve stuck in the normally closed or open position, resulting in excessive rail pressure.

Troubleshooting method:

1) Check the oil pump return pipeline: a. Use a pressure tool to measure the oil pressure of the oil pump return port. The pressure value must be less than 1.2 bar absolute pressure. If it is not within the range, it means that the oil pump return pipe is blocked; b. Fully release the oil pump return pipe, start the engine and see if the fault disappears. If the fault disappears, the oil pump return pipe is blocked. If the fault does not disappear, check the high-pressure pump. 2) High-pressure pump troubleshooting: Method 1: Change the new oil pump to do the crossover test; Method 2: The high pressure tool measures the build pressure capacity of the oil pump.