1994 Honda Civic Bubbling Noise

My Honda, a few days ago (4/17/08), began making a bubbling noise; that you could hear from the exhaust. I did a tune up replacing the spark plugs and wires. Yet when I turn the car on, it shakes REALLY HARD (almost like an earthquake is happening), and it just REEKS of gasoline. The engine/ car shakes when it is trying to idle. We replaced the PCV plug, still nothing worked. I do have a broken piston ring and am replacing it soon, yet this problem has become unexpected and annoying to deal with. We can't find the problem and have asked several mechanics what do they think the problem is and they have all said, 'check the spark plugs and filters.' We think it is the fuel injectors but we just have no idea what it is. If you could help that would be AWESOME! Thank you--