If there are no instruments, at least a speed sensor is required, connected according to the operating manual. At observance of recommendations idle adjustment should not cause difficulties. On an engine with electronic idle speed control, no adjustment operation is necessary. The system is installed on cars with automatic gearbox and air conditioning. Some differences exist between pneumatic and electronic idle boost systems. When adjusting idle speed, proceed as follows:
- make sure that the throttle control pedal linkage is free and not stuck. The latter is often the cause of increased idling;
- start the engine and bring it to operating temperature;
- check idle speed. For an engine with a pneumatic boost system, this figure should be (750±50) min–1, with electronic — (720±10) min-1. Otherwise, adjustment is required;
Pic. 172. Disconnecting the rod (1) accelerator from the lever (2)
- according to fig. 172 Disconnect rod 1 from throttle lever 2.
Pic. 173. Location of the fuel pressure regulator: 1 - locknut; 2 - regulator; 3 - vacuum hose
Pic. 174. Idling adjustment
The idle speed is set on the fuel pressure regulator, the location of which is shown in fig. 173. To adjust, loosen the locknut 1 and turn the regulator 2. First disconnect the vacuum hose 3 from it. The adjustment operation is shown in fig. 174, which shows that the locknut fastening must be loosened with an open-end wrench. Reinsert the hose after adjustment.