Hi Alfred,
    Check the afm (air flow meter) . Pop off the plastic top, you will see a wiper contact that slides on a black carbon track (variable resistor).  Look for a worn place  in the track. If worn there are many posts in the archives on how to move the resistor plate and have a fresh track or you can replace the afm. Your afm resistor might be worn at the engine load range where troubles are noticed. On type 2 / bus your problem was often referred as a bucking bus.  
Darrell
  ----- Original Message ----- 
  From: Alfred Bagdan 
  To: vanagon@GERRY.VANAGON.COM 
  Sent: Saturday, July 10, 1999 1:10 AM
  Subject: 85 Vanagon dying while driving

  Hi my name is Alfred.
  Can anyone help with this problem I am having with my 85 Vanagon 1.9 standard transmission:
  Starts fine when cold, runs fine until hot, also runs fine at highway driving but when in slow traffic occasionally starts 
  violent bucking. Also when slowing down it can't have a nice even pull. It seems to have a lot of play in the throttle, i.e. it surges too much or slows too much.  
  Another problem is that sometimes when easing up on the gas or going down hill the engine dies.  To fix this I simply turn off the ignition key and turn it on again (standard transmission) and it runs fine until next time which may be tomorrow or next week, its totally unpredictable.
  I have already had the temperature sensor problem years ago, but this problem is different.  Van starts when hot but runs rough at slow speeds while driving.(Idling when parked runs fine too)
  Thanks in advance for any help.

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