I opened this for like the 3rd time and I just realized that I think I have a related problem with the company sprinter I have been driving. Let me explain my situation and tell me if its the same.
When I was given the van, I was told that they think the floor matt moves and gets stuck and prevents it from accelerating once in a while. I didn't believe it. So when it first happened to me, I eventually pulled over. Tried playing with the matt. For some reason, I turned off the van and I started it and it worked.
So the next time it happened, I pulled over and re-started it and it worked. I felt like I had diagnosed it somewhat and found a solution. It didn't happen that often, maybe once every 500 miles, so it wasn't a big deal.
But if felt like it happened more on big mountainous hills and would also get triggered if I hit a pump, aka uneven concrete. But this past week, I notice its happening more and more.
What happens is, it loses power, I have a hard time keeping the speed. Most of the time I use cruise control, so I hear it and feel it slow down immediately. Then I could tell the cruise is trying to speed up to get back to speed but something won't let it, it doesn't have power. Which means, I have to pull over, stop and restart the van and it works fine again.