Fuel evaporation control system function - GF47.30-P-3013BK

MODELS 219 with engine 113.967 

MODELS 164.1 with engine 113.964 

MODELS 251 with engine 113.971 

Shows model 219 

The evaporative emission control system prevents fuel vapors escaping to atmosphere. This is done by storing the fuel vapors temporarily in the activated charcoal canister.

When the engine is running, the fuel vapors stored in the activated charcoal canister, are drawn off due to the manifold vacuum and combusted in the engine. The purge switchover valve carries out metering of fuel vapor from the activated charcoal canister and to do this is actuated on the ground side by the ME control unit.

Purging of the activated charcoal canister takes place at:

• Coolant temperature > 40°C
• Locking time after engine starts elapsed, approx. 45 seconds
• Deceleration fuel shutoff inactive.

To prevent pulse noise caused by pulsing of the purge switchover valve, a damper reservoir is located upstream of the valve.

The idle speed control prevents changes in engine speed resulting from purging. Depending on the level of charge of fuel vapor in the activated charcoal canister, the fuel-air mixture becomes richer or leaner.

Air admission to fuel tank 

Air is admitted through the activated charcoal canister. The air flows through the ventilation connection at the activated charcoal canister (77) into the fuel tank (75).

Air release from fuel tank 

The fuel tank is vented through the activated charcoal canister. The fuel vapor flows into the activated charcoal canister, where it is stored and drawn off into the intake manifold when the purging process is enabled.

During refueling the fuel vapors are collected additionally from the fuel tank and passed on to the activated charcoal filter (ORVR = Onboard Refueling Vapor Recovery). An activated charcoal canister is used with around 3, 5 liter capacity.

The activated charcoal canister shutoff valve and fuel tank pressure sensor are necessary for the checking the leak-tightness.

	Component description for the ME-SFI [ME] control unit		GF07.61-P-6000BK
	Component description for the coolant temperature sensor		GF07.04-P-6040BK
	Component description for the purge control valve		GF47.30-P-2020BK
	Component description for the activated charcoal canister		GF47.30-P-2010BK
	Purge control valve actuation, function		GF07.61-P-3013BK
	Purge system with leak test function		GF47.30-P-3016BK
	Component description for the fuel tank	Model 219	GF47.10-P-2000BK
		Models 164.1, 251	GF47.10-P-2000BM