ok I have a 1994 ford f-150 4x4 351 and sometimes i drive the truck and it shifts perfect and other times it will get really high into the rpms like 3000-4000 and then slam into the next gear this problem is very intermittent and the truck has never towed anything very heavy does not even have a hitch on it....and never has...... some times when i start it it idles rough and i need to hit the gas to keep it running but then goes away and a lot of people are telling me that the tps was known to cause the transmission to act up what do you guys think? oh btw it has

 

One thing I just found is look at the motor and transmission mounts. They can cause harsh shifting

 

Warm up the engine and transmission then do this : Fuel Injection Technical Library » How To Run a Self-Test