Day before yesterday I bought a 1996 Powerstroke Crew Cab F250 automatic with Ford tow package, cruise control, 4.10 Limited Slip rear axle and XLT trim package to replace my destroyed 1996 regular cab long bed XL with an aftermarket tow package but other wise similar.
I loved my old truck. It would pull anything, even heavily laden and using overdrive and cruise control, and you'd never know you had anything behind you.
Today I took the new truck to pick up 45 bales of hay on a utility trailer, and it did two things that worry me. The cruise control would cut out, even with an unloaded trailer. Now this truck came with a bad cigarette lighter (good fuse) and no fuse in the power point socket. I put the correct Power Point fuse in, and the socket worked, so I left it in. I'm worried that the cruise control cutting out may somehow be connected to the fact that the Power Point had no fuse and the cigarette lighter doesn't work. Don't want to contemplate an electrical meltdown. But I am. Why would the cruise cut out?
The other thing I noticed worried me even more. Coming home with the loaded trailer, the truck would sporadically jump the RPMs about 300, even when the MPH stayed constant. It was almost like it was hunting for overdrive, since this seemed to happen from 55 to 65 mph. Didn't notice this with the unloaded trailer and I think I would if it had happened. My 95 Powerstroke didn't do this. Miles per gallon on the 96 Crew Cab suck. It seems to use twice as much diesel as my old one.
So what's going on with the RPM jumps? I'm sure that's affecting fuel economy. Is this going to be a major repair, like a new computer?
If not, what is it likely to be and what can I do to improve fuel efficiency?