PART A - Engine, Engine Management and Turbocharger

2. Electronic Engine Management General Description

The Sierra Cosworth is fitted with a combined Electronic Engine Management System with fuel injection from Weber and ignition system from Marelli.

The electronic fuel injection system is in many respects very Similar to the EFI system available for Scorpio and Sierra vehicles.

An electric fuel pump feeds fuel from the fuel tank through a fuel filter to the fuel rail with its four injectors (one per cylinder).

The injector "on" time is individually controlled for each cylinder by the Electronic Control Unit ECU.

Inlet air passes from the aircleaner through the turbocharger, the air to air charge cooler, the throttle body, the airchamber and inlet manifold to the individual cylinders.

Electronic Engine Management - Fuel and Air System
1 = Fuel tank A = Air cleaner
2 = Fuel pump B = Turbocharger
3 = Fuel filter C = Air to air charge cooler (intercooler)

4 = Fuel rail D = Throttle bOdy
5 = Pressure regulator E = Air chamber
6 = Fuel injector F = Inlet manifold
7 = Electronic Control Unit (ECU)
8 = Pressurised fuel
9 = Non-pressurised fuel

The ignition is of the inductive discharge type with dwell control in the ignition module and the advance curves are stored by the ECU.

Electronic Engine Management - Ignition System

1 = Electronic Control Unit (ECU)
2 = Distributor with Phase sensor
3 = Crankshaft pulley
4 = RPM / TDC-Sensor
5 = Ignition module
6 = Ignition coil

A number of sensors feed a continuous stream of information signals to the ECU module thereby enabling the ECU to determine the required air fuel ratio and the spark timing.

The individual components of the engine management system are described on the fOllowing pages.