My rig has the workhorse chassis with the Chevy V8 with only 11k miles. On my first trip out it developed two issues that may or may not be related. It started on my trip from Memphis to Port St. Joe, Florida. About seven hours into the trip and several stops it was dinner time. I stopped at a Jack's burger joint. I was gone for about 15 minutes.
When I restarted the rig it started fine but started chugging and died when I pressed the accelerator. I restarted the engine fine and it moved about 20 feet before it started chugging and dies again. Being somewhat stubborn, I restarted it for the third time and it started yet again fine. This time I got to the interstate acceleration on ramp, I reached the max speed of 37 before it started chugging and died. At this point I called for a tow. It took about an hour and twenty minutes for them to arrive.
Since they had a medium wrecker not a large, I suggested to try starting it. It stared and ran fine, except for one some chug that it recovered from, for about a 12 mile trip back to the repair shop.
They kept it over night and could not repeat the issue after about 22 miles of driving the next day. They did check the fuel pressure and said it was acceptable.
My rig repeated the chugging and dying on more time on the trip to Florida. This time I just waited in a shady spot for 30 minutes and she restarted and ran fine.
Now on the trip back I never shut her off but she started having problem climbing hill if you wanted her to keep the original speed. This was not happening on the trip down nor before the trip. She would start backfiring and trying to lose power if you would insist on keeping your speed. But if you would lower your speed by 5 MPH or so as you climbed a hill, she would handle that fine.