I know it has been awhile since you posted this but my car did something like this about a year ago. we relpaced the distributor, timing belt, spark plugs, wires, checked all wiring, vaccum hoses, pcv valve, the coil was checked and then finally it was the o2 censors on the h-pipe.They may be hard to find depending where you live but in my area of Pa Fisher auto parts and ford dealers was the best place. Hope you get this and it helps. It took us over 2 months to figure out.