Table of contents: Preparatory actions ↓ Adjustment ↓
With the KE-Motronic system, there is no option to adjust the speed. The CO content, on the other hand, is adjustable. This requires an accurate gas analyzer.
To carry out the adjustment, the ignition timing must be set correctly, which for the engines described with the characteristic stored in memory usually does not change. The idle speed stabilization system must operate (the valve rings and vibrates when the ignition is on). As a rule, for engines, the nominal idle speed is 700-90 rpm, the CO content is 1.0±0.5% vol.
Preparatory actions
First, you need to interrogate the memory of the self-diagnostic system.
If there is no fault message, check the ignition timing and CO content. Idle speed can only be checked, but not adjusted.
To adjust the CO content, use the Allen screw on the air quantity meter (remove the blue cap). When screwed in, the CO content decreases; when unscrewed, it increases.
Attention. Be careful when turning the adjustment screw. The screw must not be lifted or pressed down. While the adjustment key is installed, do not apply "gas", otherwise the key may bend. After each adjustment stage, remove the key and apply a little "gas" while reading the CO value on the device.
The engine must be warmed up to a coolant temperature of at least 80°C.
Measuring instruments should be connected with the ignition off.
Connect the CO probe to the CO exhaust tube.
When conducting the inspection, do not turn on electrical consumers or the air conditioning system.
Note: The self-diagnosis system plugs are located under the gearshift lever boot. On a vehicle with ABS, there are four plugs. Only three of them are related to the KE-Motronic system.
1 Blue
2 Brown
4. Black. The brown plug marked with the number 3 is used to test the LAN system
Adjustment
Start the engine and read the measured value.
If codes 2-3-4-3 or 2-3-4-4 appear when polling the self-diagnostic system memory, it is necessary to adjust the CO content.
Disconnect the engine crankcase ventilation hoses as described in the "Preparatory actions" paragraph.
Disconnect the hose from the pressure regulator in the mixture regulator and install an adapter cable between the plug and the pressure regulator. As a last resort, make the cable yourself.
Connect an ammeter set to the milliamp range to the measuring plug of the adapter cable.
Turn on the ignition, the current value should be 90-11 mA. When measuring in the opposite direction, change the polarity of the conductors.
Start the engine and let it idle.
Use the CO adjustment screw to set the current value to 2.5±2.5 mA.
The measured value must fluctuate, otherwise lambda control does not work.
After completing the adjustment, reset the self-diagnostic system memory.
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