Volkswagen Workshop Service and Repair Manuals

From Production date 12.07.00 starting with Chassis Nº 17YU000784 carburettor engines are fitted wih a Digital Idle Stabiliser (DIS) TCI unit Part Nº 17S 905 351 A.

The idling tuning data for above mentioned models have changed, and should be carried out as follow:

** = 6° BTDC for engine code HM when using leaded fuel.

Note:

All settings to be done with electrical consumers and air conditioner off. During setting the choke must remain inactivated.

→ Fig.1     Ignition timing

Setting procedure:

•      1-     Remove ashtray.
•      2 -     Start the engine and let the idling settle (engine at operating temperature).

•      3 -     → With the engine running, bridge pins 1 and 3 of diagnostic plug with adapter kit V.A.G 1594/A or a mini fuse (part Nº N10 261 503) and wait for ± 5 seconds to allow the timing to stabilise before setting the timing, (pin 1 is the pin found in the top row,first from the left when facing the plug) - see illustration.
•      4 -     Set the timing to 3° BTDC , Fig. 1 .
•      5 -     Set the idling to 900 rpm.
•      6 -     Set the CO content to 1.5 ± 0.25%.
•      7 -     Switch the engine off and remove bridge piece form diagnostic plug.
•      8 -     Refit ashtray.
•      9 -     The DIS system will be re-activated once the engine is started again.