Fuel Delivery and Air Induction: Description and Operation

Fig. 1 Water in fuel detector, strainer & pickup tube assembly. 1982---83 models:

Fig. 2 Fuel filter system. 1982---83 models:

Fig. 3 Fuel filter/water separator. 1984---87 G & P models:

Fig. 4 Fuel filter/water separator. 1984---87 C, K, R & V models:

COMPONENTS
The fuel system consists of a tank, fuel pickup assembly, fuel filters, mechanical fuel pump, fuel line heater, and an injection pump, injector lines and individual fuel injectors for each cylinder. On 1982---83 models, the fuel pickup incorporates a water in fuel detector, Fig. 1, primary and secondary fuel filters are used, and a water drain siphon valve is included in the system, Fig. 2. On 1984---87 models, a single fuel filter assembly is used, which includes the water in fuel sensor, water separator and drain, and the fuel heater, Figs. 3 and 4. In addition, 1984---87 models are equipped with a low pressure switch which illuminates a warning lamp should the fuel filter become clogged.



SYSTEM OPERATION
1982---83
Fuel is drawn from the fuel tank through the primary fuel filter and by the camshaft driven mechanical fuel pump. It then flows through the fuel line heater, which prevents fuel waxing, to the secondary fuel filter, which again strains contaminants from the fuel. The fuel is then directed to the high pressure rotary vane type injection pump. The injection pump meters and pressurizes the fuel, then directs it through the equal length high pressure lines to the injector nozzles.

Fig. 1 Water in fuel detector, strainer & pickup tube assembly. 1982---83 models:

Fig. 2 Fuel filter system. 1982---83 models:

WATER IN FUEL WARNING SYSTEM
1982---83
The fuel tank is equipped with a filter and water in fuel detector, Fig. 1. The filter prevents water from entering the pickup tube, allowing it instead to lay at the bottom of the fuel tank, below the tube. When the water level reaches a point where it may enter the fuel system, the detector activates a warning lamp on the dash panel, alerting the driver. A siphoning system starting at the tank and going to the rear spring hanger (C and K models) or to the midpoint of the right frame rail (G models), Fig. 2, allows the driver to attach a hose to the shut-off valve and drain the system.