Idle speed check (VW Golf 1)

It is impossible to determine the RPM of a diesel engine using conventional RPM measuring devices used for gasoline engines. The fact is that it cannot give impulses from the ignition coil, which is important for such devices. The RPM can be estimated subjectively, by the characteristic vibration.

The illustrations in the drawings show where the adjustment screws are located.

Bosch high pressure fuel pump:

• loosen the idle speed adjustment screw lock nut;
• now the adjusting screw can be turned with a screwdriver;
• screwing in causes a higher number of revolutions, turning out causes a lower number of revolutions.

Bosch high pressure fuel pump: 1 - idle speed adjustment screw lock nut (2): position 3 indicates the "speed limiter" screw, do not turn this screw under any circumstances

The idle speed adjustment screw (2) is difficult to access on a turbodiesel engine. The housing (1) of the regulator membrane prevents access to this screw. The "speed limiter" screw (3) is also indicated here.

Pump "Lucas-CAV", engine 1.5 l:

• loosen the idle speed stabilization screw lock nut;
• turn the screw counterclockwise until a gap appears.
• loosen the lock nut of the idle speed adjustment screw;
• set the number of revolutions and tighten the lock nut again securely;
• turn the idle speed stabilization screw clockwise until the speed starts to increase;
• from this position turn the screw back ½-1 turn and lock:
• let the engine run for a short time at 2000 rpm and check the idle speed again.

Pump "Lucas-CAV", engine 1.6 l:

• loosen the lock nut of the adjusting screw;
• use the adjusting screw to set the number of revolutions;
• tighten the lock nut.

For all high pressure fuel pumps, the following instruction applies: under no circumstances should the full load adjustment screw or the regulator lever lock screw be turned.

Control parameters

Engine	1.5/1.6 l until September 1982	1.5 l	1.6 l since September 1982	1.6 l	1.6L turbodiesel
High pressure fuel pump	"Bosch"	"Lucas-CAV"	"Bosch" after No.068 130 107J	"Lucas-CAV"	"Bosch"
Manual transmission	825±25 min	830+30-70 min	950±30 min	950±30 min	950±30 min
Automatic transmission	930±30 min	—	930±30 min	—	—