I went out to start my car this morning, and it took forever, kept firing like it wanted to start, and then not. Finally did get it started, but the engine is running like crapo! Real rough, seems to idle ok, muffler is puffing, like it's not firing well. Checked the cap, it's on good, all plug wires are on good, new condenser a month ago or so (it's been fine till now, so I guess it still is) new coil When you try to rev the engine a little, it shakes like it's going to falls right out of the car, but eventually seems to smooth out when you hold it. But from idle, hit the gas and hang on! What could be causing it to shake so?