Fuel Delivery and Air Induction: Description and Operation

The system used on 1983 - 85 4-97.6 engines, 1983 - 87 4-140 turbocharged engines and 1986 - 87 V6-182 and 4-116 engines, is a multi-point, pulse time, mass air flow fuel injection system. Fuel is metered into the intake air stream through either four or six injectors mounted on a tuned intake manifold.
The system used on 1986 - 88 V8-302 engines is a sequential, multi-point, pulse time, speed density control fuel injection system. Fuel is metered into the intake air stream through eight injectors mounted on a tuned intake manifold. All 1988 models use this system.
In both systems, an electronic control unit (ECU) receives signals from various engine sensors and computes the required rate of fuel flow to maintain an optimum air/fuel ratio throughout the entire range of engine operation. The ECU then sends a command to the fuel injectors to meter the appropriate quantity of fuel.
The EFI system can be divided into four basic sub-systems: fuel delivery, air induction, sensors and ECU.
On four and six cylinder engine applications, the fuel delivery system consists of a chassis-mounted (four cylinder) or tank-mounted (six cylinder), high pressure electric fuel pump which delivers fuel from the fuel tank through a fuel filter to the fuel charging manifold assembly.
On eight cylinder engine applications, the fuel delivery system consists of a low pressure tank-mounted fuel pump, a fuel filter/reservoir combination and a high pressure electric fuel pump which delivers fuel from the fuel tank through a fuel filter to the fuel charging manifold assembly.
The fuel charging manifold assembly, houses the injectors which are mounted directly above each of the engine's intake ports. When energized, the injectors spray a metered quantity of fuel into the intake air stream.

Fig. 2a Exploded view of fuel charging assembly. 4-140 turbocharged engine (Mustang SVO):

Fig. 2b Exploded view of fuel charging assembly. 4-140 turbocharged engine:

Exploded view of fuel charging assembly. 4-140 turbocharged engine (Mustang SVO)

Fig. 3a Exploded view of fuel charging assembly. 4-140 turbocharged engine (Exc. Mustang SVO):

Fig. 3b Exploded view of fuel charging assembly. 4-140 turbocharged(except Mustang SVO):

Exploded view of fuel charging assembly. 4-140 turbocharged engine (Exc. Mustang SVO)