Weak Fuel Pump??
I had my first problem with my 03 6.0L today while towing my 9000# travel trailer. I had towed it maybe 70 miles and then started noticing weak power. As I got off the freeway and made a right turn it just died as I got back into the throttle. I put it in neutral and coasted to a stop. I tried to start and it started right back up and drove fine for a few miles. Then started to have a periodic miss. Then under power the engine died again. Again I put it in neutral stopped and it cranked right back up. Everytime it would die it would be under a load pulling the trailer up an incline or accelerating. It is bone stock with about 147,000 miles on it.
It feels just like my 01 Dodge, which I traded for this truck, did when the lift pump went out and the injector pump was going out.
Repalced mine at 158,000 miles and it gave me the same sort of "warning" your truck is doing... then it just died one day while drving down the road.
I had to get towed to the dealer.
Do not try and drive if you do get it started or just go to the dealer. Don't keep trying to "start it" if it won't... you risk injector damage from low or no fuel pressure to lubricate the injectors.
My dealer fixed in 3 hours on a Saturday morning.



