Supra hesitating and heat not working

[1984Supra]

I have a 1984 Supra and I can't figure out why it is hesitating. I've changed the fuel pump and fuel filter, spark plugs and spark plug wires, purged the fuel injection system, taken her on some good runs on the highway, and changed the air filter, and it's still hesitating. Any ideas?

On a different note, the heat doesn't work. I can get it to blow out cold air, and only at one setting, but no heat. If anyone has any ideas, please help, I don't know what else to try.