160 the pressure regulating valve can be triggered by controller 170 and when there is a suitable trigger pulse it establishes the communication between rail 135 and return line 195 and thus also storage tank 160 in another embodiment of the present invention sensors 181 through 184 are designed as pressure sensors these sensors detect the combustion chamber pressure in the combustion chambers of the individual cylinders the resultant device operates as follows fuel pump 155 delivers fuel from the storage tank 160 to high pressure pump 145 through valve 150 high pressure pump 145 establishes a predetermined pressure in rail 135 pressures greater than 800 bar are usually achieved in rail 135 solenoid valves 130 through 133 are activated by energizing coils 140 through 143 control pulses for the coils establish the beginning and end of fuel injection through injectors 120 through 123 the control pulses are established by the controller 175 depending on different operating conditions such as the driver 39 s intention engine speed and other parameters with a common rail system continuous injection by an injector cannot be detected reliably when there is a proper mass balance in the rail this can occur for example when the solenoid valve receives current continuously or the injector is stuck or there is a leak this can lead to an unwanted increase in pressure in a cylinder that can even destroy the engine if the peak cylinder pressure or allowable temperature is exceeded the temperature in the combustion chamber of each engine cylinder is measured by sensors 181 through 184 if the temperature of one.