Ford Repair: Miss, miracle answer, mustang gt

Question
I have a 1990 Mustang GT and I am in trouble.  I have a miss and can't seem to figure out what is causing it.  I have replaces my distributor, cap, rotor, plugs, wires, fuel pump, timing chain, triple checked my timing, ran compression test on all cylinders, all of my injectors are firing and I replaced my fuel filter as well.  The problem has gotten worse and my car will not even run unless I advance my timing to about ten degrees past tdc and then it pings and overheats my engine.  I do have a code for my speed sensor but am not sure if this would cause the
problem

Answer
Justin, it sounds like you have covered just about everything. My concern is what the compression readings were, how you determined the injectors are working correctly, and if you disconnected the SPOUT connector before setting base timing.

I have this question stored and will continue to consider possibilities. I do not have a miracle answer for you, but will continue to think on it.

The speed sensor will NOT cause the problems you describe.

Is the firing order correct? The Mustang HO engine has a different firing order than other 5.0 engines. Check to make sure you have it correct: 1-3-7-2-6-5-4-8