Fuel filter, timing, ignition coil, spark plug wires, cap, rotor, air filter, plugged intake to air box, . . . windshield, rear seat, tires. Okay the last three are supposed to be a joke. Quit changing parts and find out how to test and diagnose parts from the symptoms and with a multimeter. a 1990 has a computer and a check engine light IIRC. Get the codes and start there.
Failure to burn fuel is just as likely a failure to ignite fuel from an ignition failure and can be a result of air fuel mixtures being way off due to lack of air, though this would be unusual.