what cable r u using,,? I had this same issue when I started with a 85 vette tranny,,looking thru some transstar books I noticed the replacement cable part numbers were different for the early c4's than others,,? they explained to me the cable was longer from the brackets mounting point to wrap around the tpi'S throttle arm,I tested and it was was, with the tranny side hook fixed and the adjustment the same, there was more cable on the vette version,, I got a cable from a quad setup and it worked straight up just as whitedog adjusted,, there is also a accesory spring that you can buy that goes in front of the cable hookup to remove slack from idle adjustment but compress under throttle,,
