When you say running bad? Is it just motor? Or are the lights flickering? A short in the starter or starter circuit can interfere with ignition circuit. And make motor start popping. Even as something simple like a ground. The time I had starter was acting up too. So had a better suspect than what you are describing.
It's the motor, no lights are flickering. Motor just acts like cylinders are dropping off. Next time everything runs just fine. It comes on goes, almost like its loading up but runs great the next time.
