ICM's can be good and bad at the same time is the problem. You could test it and have it pass but then throw it back on the car and be in the same problem again, then take it back out and it could test good again. Sometimes it depends on heat or the load put on it. You are asking way more from it when you give it the beans, it's working faster and harder to supply the coils.
Sometimes they show cracks or burns and othertimes not. That why I say to just swap one real fast and see if the issues go away.
