2000 si 2 problems

I have two problems one my car is overheating. And the second is when I press the gas the engine gives out it idle's funny and when I press the gas it rev's up and down I'm spitting carbon out of the exhaust black.The engine trouble didn't start until I removed the intake piping to replace a vaccum hose coming from the bottom of the throttle body to the back of the intake manifold. I also didn't have a rachet at the time so I removed the cover to reach my spark plugs. Any suggestions. Also back to the overheating. I jumped the wire from the thermostat housing and the cooling/radiator fan came on which it wasn't before. Problem? Bad wire or bad thermostat.? Please give me some knowledge. I'm about to go insane.