Engine/Transmission (1998.5 - 2002) Weird drivability problem

[MEby]

Hi, I have a friend who owns a 2001 cummins with 174000 miles on it. He is having problems with it. While driving the truck on level road with the pedal at a fixed position it will slowly drop mph. Once it drops approx. 5 mph it will down shift and accelerate back to were it started from. It acts the same whether the cruise is on or off. Also this is an intermittent problem, sometimes its fine then the next time its all goofy again. He said sometimes it will stop if he restarts the truck. It has an auto trans. I believe its still on its first vp44. I would appreciate any suggestions. thanks

 

[JFaughn]

Check for codes & fuel pressure .
Maybe someone els has seen that problem .

 

[Timbeaux38]

TPS taking a dunp?

 

[MEby]

Check for codes & fuel pressure .

Maybe someone els has seen that problem .

Could you explain a little more on how fuel pressure might cause the truck to act like this?

 

[JFaughn]

To find any problem testing should be the 1st thing , with that truck / pump , the most common problem is the pump , if fuel pressure is erratic , it can cause the trans to hunt .
It could be unrelated to fuel pressure , but testing for the common problems , also the computer may pick something up .