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

ENGINE 156.980 in MODEL 164, 251 up to Model Year 8 

ENGINE 156.982 in MODEL 209 

ENGINE 156.983 in MODEL 211, 219 

ENGINE 156.984 in MODEL 216, 221 up to Model Year 8 

Fig 1: Identifying ME-SFI Post-Start Enrichment CAN Communication Diagram

Courtesy of MERCEDES-BENZ USA

After a cold start the fuel-air mixture is enriched for a short time.

The fuel which precipitates on the cylinder walls and the intake ports is compensated for by this enrichment and the engine runs smoothly. It is enriched sufficiently until a certain engine speed has stabilized (e.g. 1400 rpm for drive position "P" or "N" and a 30°C coolant temperature for about 30 seconds).

The post-start enrichment is dependent on:

• Coolant temperature at start
• Combustion cycles (period after start
• Drive position
• Correction programming with STAR DIAGNOSIS

Fig 2: Identifying ME-SFI Post-Start Enrichment Rate/Time Diagram

Courtesy of MERCEDES-BENZ USA