Major issue with '95 F250 250,000 miles. runs great under 40 mph. no smoke ever. Once I accelerate to 50 mph, such as when getting on the interstate, engine vibrates to the point of almost hoping out of truck and loses all power. I had to stop on the side of the road controlling idle for it not to stall. After about 3 minutes can continue on but if I reach 50 mph same thing happens. Barely made to a shop's parking lot last night and waiting for them to open this morning. Any ideas what this might be. I need the truck Monday morning.
Thanks
Thanks