|
The D Jetronic system developed by Bosch was first fitted in the mid 1980's to various european vehicles. D-Jetronic is a "multi-port," electronically-controlled Manifold Pressure Controlled (MPC) system. The air is drawn into the motor through a throttle body just the same way as in a carburetted motor. The injector injects an atomized spray of fuel into the airflow directly outboard of each intake valve. How much fuel is determined by a computer known as the Control box (in the old days) now known as Electronic Control Unit (ECU). Fuel is supplied to the injectors at a constant, regulated pressure and flow. Each injector contains a small solenoid which opens the flow fully on or shuts it fully off. The ECU's job is to determine how much fuel is needed and then control how long the injectors are held open during each piston stroke. Ignition timing is controlled using a normal distributor with contact breaker points which contains bob-weights and springs. Since the D Jet system relies primarily on the engine vacuum to determine the amount of fuel injected, the condition of the engine, tappet adjustment and ignition timing are critical to the correct operation of this system. |
|
|
|
|
