Volkswagen Golf/Jetta 2 manual

Throttle valve switches - testing and adjustment
Fuel and exhaust systems - Digifant fuel injection / Throttle valve switches - testing and adjustment

1 There are two throttle valve switches.

Switch 1 monitors the throttle valve closed position and switch 2 monitors the throttle valve fully open position (see illustration).

5.1 Throttle valve housing components
5.1 Throttle valve housing components

A Front crankcase ventilation valve B Vacuum hose connection from fuel pressure regulator C Vacuum hose from air cleaner temperature regulator 1 Air inlet hose
2 Bolt
3 Idle speed adjustment
4 Throttle valve switch 1 5 Throttle valve switch 2 6 Throttle valve housing 7 Gasket
8 Bracket
9 Bolt
10 Inlet manifold
11 Vacuum hose to brake servo unit 12 Idle speed stabilisation control valve 13 Support
14 Gasket
15 Support
16 Bolt
17 Bolt
18 Bracket

2 Disconnect the supply plug from switch 2 and check that approximately 5 volts is available across the two terminals with the ignition switched on. If not, check the wiring from the control unit.

3 Connect an ohmmeter across the terminals of switch 2, then slowly open the throttle valve until the switch points close. The gap at the throttle lever stop must be 0.20 to 0.60 mm when the points close. If necessary, adjust the position of switch 1.

4 A piece of card marked with 10° is required to check switch 2. Attach the card to the first stage throttle valve shaft.

5 Fully open the throttle and align a datum with 0° on the card. Close the throttle by approximately 20°, then slowly open it until switch 2 points close. This should occur at 10° ± 2° before full throttle. If necessary, adjust the position of switch 2. Note that the throttle valve lever roller must contact the sloping part of switch 2.

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