The system does not require maintenance, except for checking the idle speed and periodic replacement of the fuel and air filters. The most basic adjustments are described below, all other work should be left to specialists in injection systems or representatives of the VW company. Adjustment of idle speed and CO content in the exhaust gases is described in Chapter "Engine adjustment".
Air flow sensor
The air flow sensor plate must be positioned concentrically in the housing diffuser. Visually check the position of the plate, if necessary, loosen the central screw and move the plate to the desired position. Tighten the screw.
The operation of the plate lever and the adjusting plunger can be checked as follows:
Turn on the starter for about 10 seconds. Lift the sensor plate with a screwdriver (drawing W:30) — the lever should provide the same resistance throughout its entire travel. When quickly moving the lever down, there should be no resistance, otherwise replace the air flow sensor.
If the lever moves up with difficulty, this indicates that the control plunger is jammed. Inspect, clean and repair the plunger and sensor, replace them if necessary.
Check the initial position of the air flow sensor plate at normal engine operating temperature after turning on the starter for 10-15 s. The upper edge of the plate should be at the same level, or no more than 0.5 mm below the beginning of the narrow part of the diffuser (drawing W:31). If adjustment is necessary, lift the sensor plate and squeeze or straighten the wire clip under the plate slightly (drawing W:32). Do not bend the flat spring at the plate stop.
Check the idle speed and the CO content in the exhaust gases (see chapter "Engine adjustment").
Fuel distributor
The cause of difficult engine starting may be contamination, corrosion or jamming of the plunger of the pressure control valve in the fuel distributor. To repair the valve, there is a repair kit containing all the necessary seals and parts.
(The original information is posted on the resource: «VWmanual»)
Before removing the valve, relieve pressure in the system by disconnecting the high-pressure line from the engine warm-up regulator on the side of the cylinder block, near the oil dipstick. The high-pressure line has a large coupling. When loosening the bolt, cover the connection with a rag to prevent fuel from splashing.
Unscrew the pressure control valve from the fuel distributor and remove its parts, remembering their relative positions (drawing W:33). Save and reinstall the adjusting washers installed under the valve plug and spring, as their thickness is determined at the factory and should not be changed.
Clean the parts and reassemble the unit using new O-rings (shown by arrows in the figure). Tighten the valve plug to the torque specified in the section "Technical data". Connect the high pressure line to the engine warm-up mode regulator.
Injectors
The injectors, one for each cylinder, are tightly inserted into the intake ports from the rear (in relation to the car) sides of the cylinder head.
The K-Jetronic system is a continuous fuel injection system, meaning all four injectors continuously inject fuel into the cylinder head intake ports. To check an injector, remove it from the cylinder head hole, start the engine and run it on three cylinders. The jet of fuel sprayed from the injector nozzle should have a symmetrical conical shape. Otherwise, the needle or the spray spring inside the injector is damaged and the injector must be replaced.
Injectors cannot be disassembled, cleaned or repaired.
Before installing the injector, inspect the rubber sealing ring and replace it if necessary. Wet the seal and the injector with fuel, insert it into the cylinder head and make sure it is completely in the hole.
Visitor comments