ME-SFI starting function

Start quantity control

Depending upon the coolant temperature, additional fuel is injected during the starting procedure to facilitate starting the cold engineThe increased quantity of fuel injected is achieved by extending the injection time.

Post-start enrichment

After starting the engine from cold, it is necessary to enrich the mixture with additional fuel for a short time. The fuel which precipitates on the cylinder walls, is compensated for by this enrichment, and the engine runs smoothly.

Synchronization of fuel injection and firing order

In order to achieve correct assignment of the fuel injection and firing order to the respective cylinder, the sequence is synchronized during the first engine revolutions. To do this the motor electronics control module requires the signals from the camshaft position sensor and crankshaft position sensor.

Ignition at engine start

When the engine is started up to around 500 rpm, the ignition timing is controlled only through signals from the camshaft position sensor. Only once the engine speed has reached approx. 600 rpm is a transition made from the fixed ignition timing point to the ignition timing point calculated in line with the momentary operating state.

Starter control

The solenoid switch of the starter (circuit 50) is actuated through the starter relay by the engine control module.

The drive authorization system blocks the engine control. The starter rotates, however the engine does not start.

It is no longer possible to start the engine under a 9 V battery open-circuit voltage.