Engine misfire

At first I did not notice it started gradually but with time like three weeks it became so obvious that each time I try to accelerate the car starts vibrating and jerking, but it only happens when is very warm; for instance when I start the car in the morning it does not do it but after a few minutes drive when it is very warm it starts. However, if I glide with the speed engine I do not notice the vibration or the jerking, but if I accelerate it starts it starts around 2000 rpm. If I allow it to cool down it will not to do it until it gets warm. So here are the list of things I have done just to solve the problem: I have replaced my fuel pump, I have replaced my speed sensors all four, I have also disconnected the long drive shaft that goes to the back axle just to rule out that the not the pipe is not coming from the back. I have also disconnected the brake drive shaft both sides just to rule them out. But, still the problem it is still there. It did not change a thing. I have also disconnected the power plug that goes into ABS just to rule it out also, but I am still getting the same problem. Please I need your help. Note I am from West Africa we do not have a lot of good mechanics around here and the dealer's are extremely expensive so I do stuff my self and a friend.