The throttle control cable is secured with a clamp (arrow) on the spherical head of the throttle lever of the high-pressure fuel pump. After installation, the throttle control cable (4) must be adjusted by pulling the knurled end of the cable (3) out of the support (1) so far that the throttle lever rests against the full-load limit screw. In this position, tighten the safety clamp (2). The number "5" marks the "fast" idle diaphragm box on the Roto high-pressure fuel pump.
The cable between the gas pedal and the high-pressure fuel pump is very susceptible to breakage. A clear sign of damage to the throttle control cable is a heavy stroke of the gas pedal.
Removal the throttle control cable
1. Remove the throttle control cable from the gas pedal by sliding the safety clip back.
2. Remove the throttle cable from the high-pressure fuel pump (HPFP) throttle lever and remove it from the support bracket by loosening the safety clamp.
3. Pull the throttle cable out through the front wall of the engine compartment.
Installing the Throttle Control Cable
1. Ask an assistant to press the gas pedal.
2. Move the high pressure fuel pump throttle lever by pulling it by the adjusting device until it contacts the full load limiter.
3. After moving the safety clamp, reinsert the cable into the ratchet stop.
4. Control: when the gas pedal is fully depressed, the fuel injection pump lever should rest directly against the limiter without tension.
In case of malfunction, the microswitch on the throttle lever and the electromagnetic switch (1) should be checked for electrical continuity. Then check the connection of the low-pressure hoses (2) and the serviceability of the valve (3), (4) - gas recirculation pipeline.
The thermostat (2) of the coolant pipeline (1) must maintain a vacuum at t=20°C. The low-pressure pipelines (3) must be tightly secured at the joints. Further: when the low-pressure pipeline is removed from the recirculation valve, the valve must knock, the idle speed must change within 2-3 seconds. Otherwise, the valve membrane is faulty or jammed.