ME-SFI post-start enrichment function - GF07.61-P-3011M

ENGINE 275.950 in MODEL 215, 220

ENGINE 275.951 in MODEL 230 up to Model Year 8

ENGINE 275.953 in MODEL 216, 221 up to Model Year 8

ENGINE 275.954 in MODEL 230 up to Model Year 8

ENGINE 275.980 in MODEL 215, 220

ENGINE 275.981 in MODEL 230 up to Model Year 8

ENGINE 275.982 in MODEL 216, 221 up to Model Year 8

ENGINE 285.950 in MODEL 240

ENGINE 285.980 in MODEL 240

Fig 1: Identifying ME-SFI Post-Start Enrichment Function Diagram

Courtesy of MERCEDES-BENZ USA

Fig 2: Identifying Mixture Enrichment Rate Graph

Courtesy of MERCEDES-BENZ USA

Task

Enrich the fuel-air mixture for a short time after a cold start to ensure that the engine runs smoothly.

Design/function

Post-start enrichment is dependent on:

Coolant temperature at start
Duration after start
Selector lever position
Correction programming

Post-start enrichment compensates for the fuel which precipitates on the cylinder walls. It is enriched sufficiently until a certain engine speed has stabilized (e.g. 1400 rpm with no gear engaged at +30 ° C coolant temperature for about 30 s).

ME-SFI control unit, location/task/design/ function	GF07.61-P-5000M
Coolant temperature sensor, location/task/ design/function	GF07.04-P-5026M
Crankshaft position sensor, location/task/ design/function	GF07.04-P-4116M
Pressure sensor upstream of throttle valve actuator, location/task/function	GF07.04-P-5048M
Pressure sensor downstream of throttle valve actuator, location/task/function	GF07.04-P-5049M
Throttle valve actuator, location/task/design/ function	GF30.22-P-4101M
Fuel injection valve, location/task/design/ function	GF07.03-P-5004M
Correction programming, function	GF07.61-P-3031M