Volkswagen Front Wheel Drive 1974-1989 Repair Guide

Throttle Body

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REMOVAL & INSTALLATION



  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air intake hose from the throttle body.
  4.  
  5. Label and disconnect the vacuum hoses from the throttle body.
  6.  
  7. Disconnect the accelerator cable from the throttle body.
  8.  
  9. Remove the bolts securing the throttle body, then remove it.
  10.  
  11. Clean the gasket mating surface and discard the old gasket.
  12.  

To install:
  1. Install the throttle body with a new gasket.
  2.  
  3. Thread the bolts in by hand first, then tighten them to 14 ft. lbs. (20 Nm).
  4.  
  5. Connect the vacuum hoses and accelerator cable to the throttle body.
  6.  
  7. Adjust the throttle valve basic setting and the throttle cable.
  8.  
  9. Install the air intake hose.
  10.  
  11. Connect the battery cable.
  12.  
  13. Adjust the idle speed.
  14.  

ADJUSTMENTS



Basic Setting
  1. On 5-cylinder models, disconnect the accelerator cable from the throttle body.
  2.  
  3. Back the throttle valve adjusting screw out until a gap occurs between the screw and the throttle stop.
  4.  
  5. Slide a thin piece of paper between the screw and the throttle stop. Turn the screw in until the paper will not slide out, plus an additional 1 / 2 turn.
  6.  
  7. On 5-cylinder models, connect the accelerator cable.
  8.  
  9. Adjust the accelerator cable.
  10.  

Accelerator Cable
1985-89 SCIROCCO AND CABRIOLET (8-VALVE/AUTOMATIC TRANSAXLE)
  1. Place the selector lever in the P position.
  2.  
  3. Loosen the accelerator cable adjusting nut and disconnect the accelerator cable from the throttle lever.
  4.  
  5. Loosen the throttle cable adjusting nut and locknut.
  6.  
  7. Pull the throttle cable out until all play is removed from the cable. While doing this the throttle valves must remain closed and the transaxle operating lever must be in the closed position.
  8.  
  9. When the play is removed from the cable tighten the adjusting nut against the cable bracket and tighten the locknut.
  10.  
  11. Connect the accelerator pedal cable.
  12.  
  13. Have an assistant press the accelerator cable until the operating lever on the transaxle lever contacts the kick-down stop. Turn the adjusting nut to hold the cable in this position and tighten the locknut.
  14.  

QUANTUM 5-CYLINDER

If the linkage is out of adjustment, the transaxle will shift poorly. The adjustment is correct when the throttle valve and transaxle operating lever rest against the stop in the idle position. If not, adjust as follows.

  1. Remove the circlips at the ball sockets.
  2.  
  3. Remove the pushrod at the ball pin.
  4.  
  5. Move the throttle linkage against the idle stop, then push the linkage against the bracket stop.
  6.  
  7. Adjust the length of the pushrod so that the ball socket will drop onto the ball without moving the linkage off the stop or tensioning the cable.
  8.  
  9. Install the ball socket circlips.
  10.  

1985-89 GOLF AND JETTA (8-VALVE/AUTOMATIC TRANSAXLE)
  1. Warm up the engine to normal operating temperature, then shut it off.
  2.  
  3. Place the shifter lever in the Park position.
  4.  
  5. Loosen the accelerator pedal adjustment nut and set the cable off to the side.
  6.  
  7. Loosen the nuts on the cable jacket.
  8.  
  9. Pull the cable jacket out until all play is removed from the cable. While doing this the throttle plates must remain closed and the transaxle linkage must stay in the no-throttle position.
  10.  
  11. When all the play is removed, tighten the jacket nuts.
  12.  
  13. Connect the accelerator cable and have an assistant depress the gas pedal all the way down.
  14.  
  15. Turn the cable adjusting nut until the transaxle accelerator linkage contacts the kick-down stop. Tighten the cable locknut.
  16.  

1985-89 GOLF, JETTA AND FOX (8-VALVE/MANUAL TRANSAXLE)

To check the throttle cable adjustment, have an assistant press the gas pedal all the way to the floor. Open the hood and make sure the throttle valve just reaches the full throttle position. There should be approximately 0.04 in. (1mm) clearance between the throttle valve and the throttle valve stop. If not, adjust the throttle cable as follows:

  1. Pull the throttle cable adjusting grommet out of the adjusting bracket.
  2.  
  3. Remove the positioning clip until the throttle valve just reaches the full throttle position.
  4.  
  5. Install the positioning clip.
  6.  
  7. Push the grommet back into the retaining bracket. Re-check the gap and adjust as necessary.
  8.  

Remember, if there is no play in the cable the throttle lever will bottom out and stretch the cable. If there is too much play, transaxle performance will be reduced.

16-VALVE ENGINES

On the 16-valve engine, the accelerator cable is adjusted by moving the retainer clip on the notched cable housing. The cable is properly adjusted when the gas pedal is fully depressed, there is about 0.039 in. (1mm) of play before contacting the stop at the wide open throttle position.

OTHER MODELS
  1. Check that the throttle valve is closed (in the idle position).
  2.  
  3. If adjustment is necessary, loosen locknut and turn the adjusting nut until the throttle cable is free of slack or tension.
  4.  

On automatic transaxle models, make sure the throttle cable levers on the transaxle are moved the whole way into their rest positions. Some models do not use transaxle cables.

 
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