I had the same symptom when my fuel pump was going out. The first instance of it happening was several seconds of on again, off again power and then it cleaned up and was fine for several hundred miles. It then quit completely and I flat bedded it home. After 24 hours, it worked again but I had an engine check light and only 23 psi at the check port on the right hand injector. I am waiting for a replacement at the moment.
