I have a '95 F350 Dually that I have pulled a 28 ft 5th wheel for 10 years. the last time I took it out it would pull fine but start losing speed up slight grades. It will shift down and continue but there is no speeding up. this Truck use to sling this camper around on the freeway. I pulled it from California 10 years ago. The truck misses a little what I thought was water because I could switch to the other tank and it would stop. It is not missing when losing power on the towing. the tranny is shifting a little harder that usual and I am thinking something in there is what is causing my grief.

 

When was the last time you did a tune up with plugs/wires/cap/rotor and filters?

 

And check the ECU for codes. It's OBD1, so it can have codes without setting the Check Engine light.

 

service the tranny as well. are you still running the stock exhaust? your cat converter may be starting to fail plugging the system.

how many miles are on the motor?

 

I finally figured out my power problem. it was the pickup coil on the distributor. The truck finally stopped starting. I tracked it down to the pick up coil, replaced the dist. and I have my power back.

 

Glad to read you got it going. Thanks for reporting back with the cause/resolution!