93 Lumina - rough starting, please help!

[lustofdecay]

I have a 93 Lumina Euro with 3.1 FI engine. I bought it used with 94,000 miles on it. Only problems I have with it is starting it up. I recently changed plugs and wires, but the engine still seems to have problems firing. Most of the time, I have to floor the gas and turn the key at the same time to get it started. After it starts, it jumps to 2,000 rpm, goes back down to 1,000 (makes a thumping noise), and produces a raw gas smell. After that, the engine seems to run fine. Other times, it will simply stall out and I'll have to try again. On a few occasions, it cranked, but just did not start at all.

My uncle told me that it most likely has something to do with the Idle Speed Control Solenoid, or that the E.G.R. is hanging up. Any other ideas what may be the problem?