Distributor misfiring

I checked and all the spark plugs are good, the distributor was loose but that wasn't the problem, and the distributor cap and rotor are good. Now I'm stumped because all of these are good, and I guess it's not misfiring. Any help would be appreciated, to recap it will start maybe 1 of 10 times, it rumbles and shakes and I can't hit hi rpms, it seems like it want's to bog down and die if I let go of the gas pedal, and finally if I stop the car will almost instantly die.