106671-3980 ZEXEL INJECTION-PUMP ASSEMBLY Calibration Data 1066713980 220005250a

Fuel and the Effect from Cold Weather
The two types of diesel fuel available for your truck engine are typically grades No. 1 and No. 2. Although No. 2 diesel fuel is the most commonly used fuel, No. 1 diesel fuel or a blend of No. 1 and No. 2, is the fuel that is best suited for cold weather operation.During cold weather operation, it may be necessary for you to use No. 2 diesel fuel since quantities of No. 1 diesel fuel are limited and generally are only available during the winter months and in the colder climates.There are three major differences between No. 1 and No. 2 diesel fuel. No. 1 diesel fuel has a lower cloud point, a lower pour point and has a lower BTU (kJ) (heat content) rating per unit volume of fuel than the average No. 2 diesel fuel.When using No. 1 diesel fuel, you may notice a drop in power and fuel efficiency, but should not experience any other operating effects.The cloud point is the temperature at which a cloud or haze of wax crystals will begin to form in the fuel and cause fuel filters to plug. The pour point is the temperature which diesel fuel will begin to thicken and be more resistant to flow through fuel pumps and lines.Be aware of these fuel values when purchasing your diesel fuel and anticipate the average outside (ambient) temperature for the area your engine will be operating. Engines fueled in one climate may not operate satisfactorily if moved to another because of problems that result from cold weather.Before troubleshooting for low power or poor performance in winter months, check the type of fuel being used.The use of starting aids, engine oil pan heaters, engine coolant heaters, fuel heaters and fuel line insulation also provide a means of minimizing starting and fuel problems in cold weather when No. 2 diesel fuel is used.Fuel Related Components in Cold Weather
ECM Fuel Cooling
Fuel Cooled Electronic ECMThe electronic control module (ECM) is fuel cooled. Fuel is routed from the tank, to a primary fuel filter, through the transfer pump, then through cored passages in the electronic control module housing, on to the secondary fuel filter, and finally to the injection pump.Inlet fuel temperature to the transfer pump must never exceed 149°F (65°C). Fuel temperatures in excess of this temperature reduce the life of the electronics, reduce the life of the transfer pump check valves, and reduce engine power availability.Fuel Tanks
Fuel tanks should contain some provision for draining water and sediment from the bottom of the tanks.Some fuel tanks use supply pipes that allow water and sediment to settle below the end of the fuel supply pipe. This water and sediment should be drained at each oil change.Some fuel tanks use supply lines that take fuel directly from the bottom of the tank. If equipped with this system, regular maintenance of the fuel system filter(s) is important.Fuel Heaters
Fuel heaters prevent plugging of the fuel filters in cold weather