Car cranks but wants to start when i release the key but wont run

I I’ll check for voltage at the ballast do you guys know what it should be reading and the motor has spark because sometimes i can get it to run when I release the key
This is what I'm talking about. Won't start in crank. If you're quick, it will start and run (with the key in the Run position) if the motor is still turning fast enough. Correct?