ME-SFI starting function - FI starting function - GF07.61-P-2003BK

ENGINE 113.967 in MODEL 219 

ENGINE 113.964 in MODEL 164.1 up to Model Year 8 

ENGINE 113.971 in MODEL 251 up to Model Year 8 

Shows model 219 

Start quantity control 

In order to facilitate starting of the engine when cold, additional fuel must be injected during starting procedure. The increased quantity of fuel injected is achieved by extending the injection time.

The start quantity control is dependent on:

• Start recognition
• Coolant temperature
• Engine speed
• Engine off time
• Altitude (atmospheric pressure).

Battery voltage and voltage supply 

The injected fuel quantity is determined by the opening times of the fuel injection valves. This opening time is dependent on the battery voltage. The ME control unit extends the injection time in order to compensate the quantity injected if, for example, the battery voltage is low. No further engine start is possible below approx. 7 V.

Post-start enrichment 

After the engine is started from cold enrichment with additional fuel is necessary for a short time.

fuel which precipitates on the cylinder walls, is compensated for by this enrichment, and the engine runs smoothly. The post-start enrichment is dependent on:

• Coolant temperature at start
• Selector lever position
• Combustion cycles after start
• Correction programming with STAR DIAGNOSIS

Synchronizing fuel injection and firing order 

In order to achieve correct synchronization of the fuel injection and firing order to the particular cylinder, the order is synchronized during the first revolutions of the engine. The ME-SFI control unit requires the signals from the camshaft Hall sensor and crankshaft Hall sensor for this purpose.

Ignition at engine start 

When the engine is started and up to approx. 500 RPM, the ignition timing point is controlled only on the basis of the signals supplied by the camshaft Hall 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 unit.

The drive authorization system inhibits the engine management system. Although the starter rotates, the engine does not start.

Parking shift lock 

With automatic transmission, the engine can only be started in selector lever position "P/N" and when the service brake is operated. The information on the selector lever position P/N comes via CAN from the transmission control unit. The information "service brake operated" comes via CAN from ESP control unit.

Fuel in the engine oil 

For a cold start, fuel may get into the engine oil. When the engine oil is heated, the fuel is reevaporated and is combusted via crankcase ventilation in the engine. The mixture deviation that occurs when the engine is idling can be up to 30%. Lambda control corrects this deviation. Mixture adaptation saves this correction as a long-term effect. A subsequent start could fail if the start mixture is too lean, although no exhalation of fuel takes place. To prevent this, the ME control unit constantly calculates the fuel quantity in the engine oil. To do this, the number of starts, the start temperature and the subsequent operating duration are evaluated.

	ME fuel supply, function		GF07.61-P-3004BK
	ME-SFI ignition system, function		GF15.12-P-0001BK
	ME engine speed signal, function		GF07.61-P-3017BK
	ME-SFI synchronization of fuel injection and firing order, function		GF07.61-P-4009BK
	Voltage supply of ME-SFI control unit, function	Model 219	GF07.61-P-5001BK
		Models 164.1, 251	GF07.61-P-5001BM
	Starter control, function		GF15.30-P-3000BK
	ME-SFI [ME] control unit, component description		GF07.61-P-6000BK
	Fuel injection valves component description		GF07.03-P-6010BK
	Camshaft Hall sensor component description		GF07.04-P-6020BK
	Coolant temperature sensor component description		GF07.04-P-6040BK