It'll run fine with it blocked off. Mine has for about 6 months and counting.
1. Remove IACV from manifold
2. Place IACV on top of gasket material (less than $4 auto parts store)
3. Trace it out on gasket material making sure to mark the bolt holes
4. Cut the material and put holes where the bolts are
5. Place gasket between IACV and intake manifold and re install it
6. Bleed coolant system


If you've got an "up/down" idle problem, try cleaning out the Fast Thermo Idle Valve. On my H23 its under the throttle body and should be in the same location on your motor. Remove it and spray the inside of it with carb cleaner. Reinstall, bleed coolant system, and finally re-adjust yor idle.