2017 Ford F450/Newmar motor home stumbles

In May of 2017, my wife and I purchased a brand new Newmar Baystar Sport Class A Motor Home. The very minute I took delivery and drove the wheels over the curb, the Ford Triton V-10 6.8-liter motor would stumble and almost die on takeoff from a stop. It did this on my first two takeoffs from red lights. I immediately returned to the selling dealer, but the motor home did not emulate the same problem on his test ride. He blamed it on my inexperience with the motor home, and claimed that I would get used to the accelerator, and all would be fine. I didn’t believe his assumption about inexperience with the motor with the machine, but drove it 70 miles home without further incident.

However, since then the motor home has displayed the same problem intermittently numerous times. At times it could go a 1,000 or more miles without the problem occurring, but at other times, it could occur 7 times in 40 miles. I found that if I slam the vehicle’s accelerator to the floor after it stumbles, it usually will take off and run in a normal fashion. The on-board computer does not record the problem, nor has a Ford mechanic experienced the problem on a test ride. Most recently the problem has advanced to be more of a concern. On a trip from Oregon to Arizona, the motor home ran great for almost 2,500 miles. Yet, twice on the latter stages of the return trip while climbing up mountains, running 55 mph and with the cruise control engaged, the motor totally shut down. Within a few seconds while still rolling forward, I jammed the accelerator twice to the floor, and the engine took off once again. As I said, this occurred twice and within 50 miles of one another. This has created a very real concern for me. If I were passing a car on a two lane road, such hesitation could lead to a head-on collision. Or if I were on a curve or even needed to brake, I lose my power steering and power brakes, and that could lead to a serious accident. Ford seems unconcerned about the problem and will not do a buy-back of this dangerous vehicle.

I am hopeful that you might be able to identify the problem and possible solution for me. I really am afraid of an accident that could lead to serious injury or death for my wife and I, as well as occupants of other vehicles that could be involved in the potential accident. Thanks for any and all input.

Brand new motor coach… That is a warranty problem caused by either the Ford engine or Newmar screwing something up during assembly. I’d hire a lawyer. I’d also video the problem and use that as evidence to both Ford and Newmar.

You have a really expensive pi$$ing match brewing not at all uncommon in the RV world and you’ll likely end up in court over this.

It sounds like a fuel delivery problem to me. Either a faulty pump, wiring or crankcase evaporation system problem. THAT last one would have Ford pointing at Newmar and Newmar pointing back.

I’d install a fuel pressure gauge and include the gauge in the video to prove it is a fuel issue or eliminate it so you can focus on ignition.

Thanks for the input. I think the fuel pressure gauge may be a good starting point.