Bucking problem

I´m having a problem with my 88 Escort. It started last Tuesday. When the car gets hot if you´re stopped it tries to stall and when you´re driving it starts bucking trying to stall and sometimes back fires, one of my friends who has an Escort said he had the same problem and that it probably was the control distributor module. On Thursday I replaced the control distrib. module, spark plug wires, cap, and rotor. I reved it up and got it real hot to see if it was still having problems but it didn´t , until today.

If anyone else has had this problem please let me know what you did to fix it. I would really appreciate it.