Scott... You are right on target! At first, I tried driving her with both TPS and ISC disconnected but mounted in position. Same result as you described but without the fence. Then I installed the new TPS (using only one screw to hold it in place) and ISC units just to see what would happen while the PB Blaster was working its magic on the fittings. Both are now connected electrically and she doesn't run worth crap: as you indicated, constantly stalling, etc. I am now thinking there is another problem because with both new units connected, the running problem should have been solved. But, of course, there is something else wrong. My current hypothesis is the computer is on the fritz as it is supposedly the controlling influence although I can't trace the wiring schematics from 'puter to either TPS or ISC. Guess I'll just have to bite the bullet and try that next after I drill out the broken screw piece. Just the wonderful world of Cadillac overdoing the electronics when it could have been done much more simply. Anyway, I keep trying to loosen the fittings on the base plate without destroying the piping, hope I'm successful with that.Scooter, I can tell you driving without a working ISC is no fun. But it is possible.
My ISC was on the fritz so I disconnected it temporarily. Lots of stalls after cold starts, some stalls even after warm starts. I couldn't use AC because the car would stall at a stop, mid drive (insufficient RPMs). I'd have to rev the engine in Neutral to keep it running before putting it in gear, which, of course, caused a jolt when you put the car in gear. That requires some running room to do safely. One time I took out a wooden fence overdoing it in reverse.
Can't be re-tapped, a little bigger?
As a side note, the FSM says there is no idle throttle adjustment that can be made: Au' Contraire, mon ami. Note to Cadillac engineers: there is an adjustment screw hidden just in front of the ISC motor which is fully capable of doing just that. Granted no fuel/air mixture available on the DFI but you can increase/decrease the idle throttle speed at your convenience. So why is the ISC needed? Rhetorical question.
AND, I could probably write a novel about the horrors pertaining to the original automatic antenna regarding the design, removal, repair and placement of said unit !! But I still love the car. What did I expect from a female.