scoobian

Ive got an issue with my car (95 WRX) running poorly at light throttle < 2k rpm
it judders on acceleration and if I maintain 1400rpm in neutral, it will rhythmically rise and fall between 900rpm and 1400rpm

today I manged to see a fault indicator on the Apexi handset and also spotted that teh idle switch is open (closed?) until 1500rpm....so I guess my problem is that the idle switch needs adjusting

questions: is it possible to adjust the idle switch 'position'?
where is the idle switch located? - OK, found the throttle position/idle switch unit
could it be summat else!?
the throttle position goes from 4.83v (no throttle) to 0.8v (WOT) with engin eoff and cold. but the voltage gets to 4.64v before the tidle switch actuates - I assume this isnt right??
your help would be appreciated, folks!