At 08:44 PM 12/07/1999 -0500, you wrote:
>I have a 1990 Vanagon that was cutting off a lot jerking the whole van from
>time to time.  After playing with the computer, air flow meter and the
>ground wires I gave up and took it to the mechanic.  They disconected the
>trottle body switch and it now works fine, but they did not know what the
>purpose of the switch is.  Should I leave the van like that or replace the
>switch?  Will driving it like that with the switch disconected damage
>something else?  Anyone knows the purpose of this trottle body switch?
>
>Sorin
>

Sorin (what a neat name), you need to find a mechanic that is knowledgable
about the vehicle and it's fuel injection system. There may be more than
one switch on the throttle body. Most Euro (Bosch and others) have a switch
to signal the computer (ECU) to run the idle system. If when hooked up, the
motor was not running properly, it means find out the source of the problem
and fix it because it MIGHT cause damage or break you down with no notice.
The switch is very easily tested by any apprentice mechanic. Replace it if
it's bad. If it's good, continued testing of FI system components is
required to find the source of the problem.

You need a VW savvy mechanic to run some test procedures in orderly
fashion, the Bentley diagnostic procedures, that is. You do not wany anyone
playing 'poke and hope' with that system if you value your Kronars.

T.P. Stephens aka Doktor Tim
Surveyor, Mechanic, Poet, Philosopher
San Juan Island, WA