Abstract: An electronic device controlling the intake manifold heater and priming fluid injection system in diesel engines. The device automatically energizes the intake manifold heater and enables the priming fluid injector in response to electrical signals received from a coolant temperature sensor and a lubricating oil pressure sensor so as to improve cold starting, cold driveability, fuel consumption, gas emissions, and to eliminate white smoke at the exhaust. The device prevents the priming fluid injector from being operated until after the intake manifold heater has cooled to a level preventing ignition of the priming fluid, such as ether, in the intake manifold.