If loosening the throttle cable helped then maybe try loosening it just a bit more. It still might be a little too tight. Here is one thing to try. Next time your motor is warm and idling high, pop the hood and try to manually close the throttle plate. Just push on the throttle lever so that you are taking up any possible slack in the throttle cable. If the idle drops then the cable is still too tight.
Also, in response to your previous question, no I did not disconnect the ISC when adjusting the BISS. Have you actually used an ohmeter to test the resistance of the ISC coils? Maybe remove the ISC and clean the carbon deposits off of the tip. A little bit of brake cleaner and a toothbrush will take care of it. Maybe even clean out the TB itself.
I don't know if this helps but I found this thread of someone with a similar problem:
car dies when clutch is in maybe flywheel
It easy enough to increase your idle so it may be worth giving it a shot. Just back the BISS out a bit.