I had an unusual hesitation, then a complete stall, on my '85 500SEC.
In checking all my fuses, I opened the clear top on the OVP. To my amazement, the fuse fell out into my hand!!
I pulled the whole thing out and took the red top off. I found that the THIN aluminum contacts for the fuse had loosened. I took a fine pair of needle nose pliers and GENTLY squeezed the contacts together. I replaced the fuse and it has not faltered since.
I think that the weight of the plastic end of the fuse was working as a lever arm against the contacts and forced them open over time(vibrations). Anyway, it took longer to find the problem, than fix it!!
Good luck, John F.