Attention! When working on the fuel system, it is necessary to first relieve the pressure in the system.
Relieving pressure in the fuel system
1. Remove the ground wire from the battery.
2. Slowly loosen the fuel line union nut to relieve pressure in the fuel system.
3. An alternate method of relieving fuel system pressure is to remove either the fuel pump fuse or the fuel pump relay and run the engine at idle until it stops. After completing work on the fuel system, reinstall the fuse or relay previously removed.
Examination
1. Check the reliability of the wire connections and the absence of corrosion.
2. Check the condition of the air filter and spark plugs.
3. Check the compression pressure in the engine cylinders.
4. Check the ignition timing setting.
Adjustment
Bosch L3.1 and MP3.1 systems
Before adjustment, set the idle speed and meet the following conditions:
- the ignition system must be in good condition and properly adjusted;
- the air filter must be clean;
- the initial throttle positions are correctly adjusted;
- the throttle switch is adjusted correctly;
- the engine must be warmed up, the cooling fan must turn on and off once.
1. Adjust the idle speed with the throttle valve rotation screw. Turning the screw clockwise decreases the idle speed, counterclockwise increases the speed.
2. Install the exhaust gas analyzer on the vehicle according to the manufacturer's instructions.
3. Adjust the fuel mixture composition (FMC) by turning the air flow meter screw. To access the screw, first remove the plug.
4. Adjust idle speed.
Bosch ML4.1 System
The idle speed is not adjustable. It is controlled by the idle speed control valve.
1. Install the exhaust gas analyzer on the vehicle according to the manufacturer's instructions.
2. Adjust the fuel mixture composition (FMC) by turning the air flow meter screw. To access the screw, first remove the plug. Turning the screw clockwise increases the FMC content, and counterclockwise decreases it.
Bosch LU2-Jetronic system
Adjusting the idle speed with a screw (lU2-Jetronic system)
2 – idle speed adjustment screw
The idle speed is adjusted as described for the Bosch L3.1 system (see above).
The composition of the fuel mixture is automatically adjusted by the device according to signals from the oxygen sensor.
Bosch Motronic M1.3 system
Idle speed is adjustable on 8-valve engines only; on 16-valve engines, idle speed is controlled by the ECU.
1. Adjust the idle speed with the throttle valve rotation screw. Turning the screw clockwise decreases the idle speed, counterclockwise increases the speed.
2. Install the exhaust gas analyzer on the vehicle according to the manufacturer's instructions.
3. Adjust the fuel mixture composition (FMC) by turning the air flow meter screw. To access the screw, first remove the plug.
Systems MM8P, Sagem-Lucas 4GJ, Bosch Motronic 5.1, Bosch Motronic 3.2
The systems do not have any regulation. If the idle speed or mixture composition does not correspond to the norm, then the control unit is damaged.
Original publication on the website peugeotbook.ru