'88 TQC throttle switches

[sevans@radstone.co.uk (Steve Evans)]

Could anybody tell me if the "full" throttle switch on 2226cc 10V quattros is
genuinely a switch (as the "idle" switch appears to be)? Could it be a
potentiometer or other type of transducer?

Pins 1&2 of the throttle switch connector are shorted by the switch assembly
when the throttle is in the idle position, but the connection between pins
2&3 is always open circuit. I would expect this to short at higher throttle
openings - is this the case?

If this switch is faulty then I am assuming is will prevent the frequency
valve, as shown in Bill Samaras's diagram of 1 Sept '94, from switching, hence
inhibiting increased boost pressure :-(.

My reason for investigating this switch is that I have, since buying the car
in Jan., had occasional sudden inexplicable power surges when accelerating.
Could this be due to the switch occasionally functioning correctly? If it is
due to an increase in boost pressure then there is no evidence of excessive
boost as I understand that this results in the ECU shutting things down which
I would expect to cause a mis-fire.

Thanks in advance,

Steve Evans
'83 Triumph TR8
'88 Audi Quattro Coupe Turbo