I have a 1986 Capri 5.0 that I have been restoring. recently it has developed a miss in the engine and it is not just a single cylinder (checked headers with temp gun and pipes are all about the same). When you rev the engine (WOT) up it falls on its face and sputters until you let off the gas and then it idles fine. If you WOT it will just sputter until you let off the throttle ( could sputter for several minutes if you hold down the pedal WOT). I also noticed that all the plugs are black (way to much fuel). I have replaced the plugs, Brand new wires, TPS., Ign. module on dist.. I have noticed that when I do the volt test on the TPS the reading don't seem to change when I open the butterfly and I have put 3 different TPS sensors on it. Checked the ground on the engine harness too. The engine is all stock except a set of headers. Thank you for any input.