On the 16v KR Throttle Body there is a Grub Screw with Lock Nut just behind the ISV Micro Switch, what does this do and what does it adjust only asking as it seems to be factory set with a dab of yellow paint and has been fiddled with in the past. I wold like to set it correctly as I am trying to work out why the car will only tick over at 16/1800rpm unless I disconnect the ISV. To date I have replaced all Injectors and Seals, all Vac Pipes etc etc but problem still exists. Help would be appreciated
is it the throttle stop one?if so the haynes manual for the digifant says back it off till screw isnt touching linkage (you may have to take off the idle switch as well) then use a piece of paper between screw and throttle. move it around till you feel paper grab, then half turn further. isnt one for the 16v but cant see it being different as throttle is basically the same. It does have a procedure for the throttle switch though, you use a 0.1mm feeler between stop and lever, then adjust switch till it clicks have you replaced injectors, if you fitted ones without the top hat or you have leaky insert seals you end up with an air leak past the air shrouding system. to rule out clamp the vac line between the breather hose and the inlet this thread worth a read: https://clubgti.com/forums/index.ph...air-and-tune-your-mk2-corrado-1-8-16v.195423/
John Thanks you for the reply, Injectors were replaced with the correct Bosch ones as original, I also replaced all the seals and the inner shroud. I have now set the throttle stop screw as per instructions and also reset the micro switch and it does seem to have dropped the tick over to 1000rpm so that's good. Just one question should the ISV buzz all the time when warm or should it stop when the throttle is opened and the micro switch has clicked out ??
good stuff so far as I know it should always buzz regardless of temp, but I never tested it all that much on mine just a 'switch ign on cold make sure it buzzes' test
ISV should be buzzing all the time and is not temperature dependent - the only reason I know this is that I have disconnected the ISV at various temperatures and there is always voltage at the connector.
