Tachometer going insane and loss of power!!

[mark240sxx]

Today i was driving earlier and everything was fine, then parked my car for about 20 minutes, got back in, started up fine then on the freeway my rpm starting fluttering and when i would give the car gas nothing would happen as if i was losing power. The same thing was happening on the street if i would give it gas it would not gain speed and the rpm would flutter at the rpm it was at. I couldnt get past 2500rpm without it start fluttering.

Any advice is appreciated.