ME-SFI warm-up control, function

P07.61-2691-01

t1 Start quantity control (duration e.g. 2 s)

t2 Post-start enrichment (duration e.g. 15 seconds at coolant temperature of 15°C)

t3 Warm-up control (duration in line with coolant temperature)

a Start

b Start of cutoff of post-start enrichment

c Start of warm-up control

t Time

A Enrichment rate

After the start quantity control or post-start enrichment, the fuel/air mixture continues to be enriched via the warm-up control.

The fuel precipitating on the still cold inside walls and thus missing during combustion, is compensated by warm-up control.

An additional quantity of fuel is metered to the engine by the ME control unit (N3/10) in line with the performance map. To do this, the actuation period of the fuel injection valves (Y62/1, Y62/2, Y62/3 and Y62/4) is extended accordingly.

Warm-up control is dependent on:

 Coolant temperature

 Intake air temperature

 Engine speed

 Engine load