got a slight problem, just got the old 1989 cummins road worthy after sitting in a field for 2 years and now i have a question, the tv cable to the transmission does it need a return spring on it to bring it back?? and would that be the reason when i smash down on the throttle she doesnt seam to wanna go over 60 mph, not fully sure on this so thats why im asking you guys

 

The TV cable on my 90 was spring loaded.
It kept the cable pulled tight at idol and pushed it in when the throttle opened.
If its not working correctly it will make it shift crazy or not at all.