I don’ t understand the shop?s approach. If this were my problem I would be hopping mad unless they could give me a good explanation. It seems to me that they are throwing parts at a problem that they don?t understand. Was fuel pressure low? If not, why replace the fuel pumps? That must have cost a bundle. If a coil is bad, you should have an individual misfire code for each cylinder. The chance of all coils going at once is rare unless someone washed the engine with a power washer. As you know, they are pretty expensive too. That is why they are not usually replaced as a set, but individually.