DFI engine stop control function

P07.13-0332-76

Design

K40 Relay module (up to 02/97)

K40/4 Fuse and relay module (as of 03/97)

L5/6 Crankshaft position sensor

N3/8 DFI control module

Y1/1 Electrohydraulic shut-off actuator

Y23/3 DFI distributor-type injection pump

Y23/3k1 DFI fuel metering actuator

Y23/3l1 Slide valve actuator

Task

Switching off engine when ignition OFF.

Function

During the engine stop operation the function of the electrohydraulic shutoff actuator (Y1/1) is tested and the engine is switched off through the fuel metering actuator (Y23/3k1).

Test requirements for the electrohydraulic shutoff actuator:

engine speed n < 800 rpm

and vehicle speed < 2.75 km/h

Ignition OFF:

The electrohydraulic shutoff actuator (Y1/1) is deenergized by the DFI control module (N3/8) and shuts off the fuel supplied to the distributor shaft. Engine speed (n) should drop to < 500 rpm within not more than 2 seconds. If this is the case, the DFI control module moves the fuel metering actuator (Y23/3k1) to zero delivery and the electrohydraulic shutoff actuator is again opened.

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If the engine is not running (n = 0 rpm), the electrohydraulic shutoff actuator is closed again.

If the test requirements are not met, the fuel metering actuator is set to zero delivery and at the same time the electrohydraulic shutoff actuator is closed. At n < 500 rpm the electrohydraulic shutoff actuator is opened again and closed at n = 0 rpm.

If engine speed is already less than 500 rpm at ignition OFF, the engine is switched off by the fuel metering actuator, the electrohydraulic shutoff actuator remains open and closes at
n = 0 rpm.

 When switching off the engine (with the exception of fault at electrohydraulic shutoff actuator and/or fuel metering actuator) the electrohydraulic shutoff actuator is always open below an engine speed of n < 500 rpm and does not close until the engine has stopped running in order to avoid the injection pipes "running empty".

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