PEC fuel injection and ignition system notes on self-adaptation of mixture formation

The lambda control determines the fuel injection time so exactly that the fuel-air ratio is always round lambda 1 (equals 14.7 kg of air to 1 kg of fuel) in all operating states.

If faults occur as a result of:

 unmetered air

 wear or carbon deposits on fuel injectors

 wear to engine

 fault in detecting intake manifold pressure

 fault in diaphragm pressure regulator

 faulty purge control

the control module automatically performs a correction of the mixture formation.

The correction variables are constantly calculated and permanently stored. Self-adaptation is performed at idle speed and at part load.

The correction in each case is maximum 25% toward a richer or leaner mixture. After completing repairwork, such as replacing the control module or the throttle flap positioning motor, the control module is once again automatically adapted after about 10 trips. After the faults stated have been rectified, the self-adaptation must be reset.

Resetting is performed by disconnecting the control module. After re-connecting the control module, it is then necessary to reactivate recognition of the vehicle version as well as recognition of the mechanical end stop of the closed throttle valve.