摘要 |
It has been found that direct-injection gasoline engines emit particulate matter during the first 500 seconds of operation due to fuel impacting combustion chamber surfaces. To largely overcome the fuel penetrating to surfaces in the combustion chamber, the fuel may be heated. In one embodiment, engine coolant that is heated in the water jacket portions nearest exhaust ducts is provided directly to a tube in physical contact with the fuel rail. In some embodiments, the tube is provided with an electric heating element. If the coolant pump is turned off at the initial portions of a cold start, the electric heater raises the temperature of the fuel in the fuel rail. After engine coolant temperature raises, water, warm coolant is provided to the tube proximate the fuel rail and the heater is turned off. |