SUPER SONIC

Hi, i need a place to start tracking down the problem of the engine hesitaion i have on my 1998 mustang. when my engine gets warm, my engine starts to hesitate severely when i engage to first gear, slowing and jolting it down. when i start engaging the clutch, it almost seems like my engine is coughing up something. i cant scan because there's no codes on the diagnostics system. if anyone knows where to start, i would gladly appreciate the help. thanks!

(my car has been in an accident a month an a half ago, could that be the cause? nothing touched the engine, but also the car has 147,000 miles on it.)