Ford Repair: 1996 Ford Mustang GT, ford mustang, mustang gt

Question
My mustang has a miss at 4000-4200 RPM.  It lacks power when it is cold.  It also idles rough when it is first started.

I have tried changing the fuel filter, fuel pump, plugs and wires, coil packs and EGR valve.  None of this has helped.  

Any Ideas?


Answer
i think the next thing you will have to try is a compression test, it may have low compression in one or two cylinders. that will definitly show a missfire with a load applied to the engine, do the compression test and let me know how it goes, good luck
Chris P