A used ISC will have play. 40 ohms is perfect for that particular unit (28-33 ohms is the range for older units). You can clean it with carb cleaner. If you had oil in your TB when you removed it, there may be oil in the ISC, which will kill the coils.

EDIT: You need to test it on the car, though. Plug it back into the harness and see if it will extend and retract through its proper range.