15fusion1.5

Long crank, starts and runs rough then dies. Need help with fuel pressures. Low side is 7 bar with key in engine off. Fuel rail is saying 68 bar when the desired is 4. If I unhook the sensor on the rail it jumps to 225 bar. Im not a mechanic but to me if I unhook a sensor then the reading should be unavailable or at least say zero, not raise. Also if the desired pressure is 4 bar but it shouldn't have 68 so I believe that sensor is the problem. But could this be caused by one of the other sensors?