VERY Interesting...Please read

hey guys!! last night in class i brought my car into the shop to diagnose the hesitation/surging problem. we checked fuel pressure, and it was normal. however, we covered up the intake above the throttle and the engine just kept on running. no change in idle, no stalling, nothing. just kept running. we had four hands covering it up but it just kept running normally. so, we took a smoke box to it and tried to locate a vacuum leak. nothing. there wasn't smoke coming out of anywhere it shouldn't have been coming from. so what is going on???? anyone have any ideas???

The air has to be getting in somewhere.
A crack somewhere, or a bad seal or gasket?

Have you noticed any drop in coolant levels since this issue started?

it's been doing this since last june, actually, and for the most part runs fine. idles okay....not sure really. maybe i'm looking at a throttle body rebuild