I got a low fuel rail pressure code (P0192), and the engine was extremely difficult to start. When it finally started, it idled roughly for a while, but then smoothed out eventually, and runs perfectly and smoothly in town, which tells me that the low pressure pump in the tank is working fine. Every morning I have the same startup issue. On the highway it will hit 70, but ANY load, such as a gentle hill or attempt to pass a vehicle, results in power loss, and on hills a power loss that drops my speed from 70 to between 35-60, depending on steepness and length of the hill. A dealership did a diagnostic and told me I needed a new High Pressure Fuel Pump. I ordered one and installed it. That did not solve the problem. Could the fuel pressure sensor be signaling a fuel dump? If so, can it be replaced without changing the entire fuel rail and sensor as a unit? (Which is what the shop manual says to do.) I think that the Fuel Pressure Regulator is in the top of the pump, with the 2 wire connector controlling it. I disconnected it to see if it made any difference, which it did not, other than setting code P0091 for the low regulator input as it should have done. The regulator should be OK since it came on the new pump. Perhaps the PCM is sending signals to the regulator to dump fuel? Perhaps secondary to a faulty Fuel Pressure Sensor? Or due to other parameter inputs? BOTTOM LINE IS, WHAT NEXT?

 

If it was mine, I'd do a pressure test on the LP fuel pump.

 

Yup, I've already ordered one. I let the fuel tank get below 1/4 full and parked it facing upward on a slight slope, about 20 degrees, and it would not start no matter how many tries. I then added 5 gallons of gas and I was able to get it started as before. This told me that the LP fuel pump was not picking up or pumping efficiently, which is reported on the forum by others. I'll let ya'll know if it solves the problem when I install it.