4. Fuel Supply

This section covers the fuel supply portion of the fuel system-the components which store the fuel and supply filtered fuel, under pressure, to the fuel injection system. The fuel injectors, which deliver fuel from the fuel injection system to the engine, are also covered in this section.

An electric transfer pump, located in the fuel tank, pumps fuel from the tank to the fuel reservoir where it can be picked up by the main electric fuel pump. The main pump supplies fuel under pressure to the fuel injection system. If, for any reason, electric power to run these pumps is interrupted, the engine will not run.

Fig. 4-1 shows the fuel reservoir, together with the main fuel pump, the fuel filter, and the fuel accumulator used on CIS, CIS-E and CIS-E Motronic systems. Digifant models are similar, but do not include the accumulator.

Absolute cleanliness is essential when working with the fuel system. Even a minute particle of dirt can cause trouble if it reaches an injector. Thoroughly clean the unions before disconnecting any of the fuel line connections. Use only clean tools. Keep removed components clean, and seal or cover them with a clean, lint-free cloth, especially if the repair cannot be finished immediately. When replacing parts, install only new, clean components. Avoid the use of compressed air nearby, and do not move the car while the fuel system is open. Seals, O-rings, and clamps should always be replaced rather than reused.

Fig. 4-1.

Fuel reservoir, main fuel pump, fuel filter, and accumulator on CIS, CIS-E, and CIS-E Motronic systems. Reservoir and pump assembly on models with Digifant is similar.