Lincoln Repair Questions? Ask a Mechanic for Answers ASAP
Ok. The fuel injectors will most likely not be causing this concern. The only way the electrical system would cause this, is of there is a broken wire to one, or more, of the coils causing the misfire. A flashing check engine light indicates a severe ignition misfire. You should probably check the codes that are stored for your check engine light after replacing the #7 coil, to see what cylinder is misfiring now. Generally the coils are the source of the misfire and flashing check engine light. I would continue to replace all the ignition coils. You need to get that out of the way. Then go from there.
You can if you want but the ebay ones are junk. I have seen them last only a few thousand miles. I would rather go to auto zone or napa or something like that. Otherwise you'll be replacing them all the time.