The 99 used J tech junk for a computer. My MTG 2500 snap on wont communicate with the decrepid at the shop I am at either.( I have the same car with a junk engine). I have had that problem with many J tech computers in 99-00 jeep and chryslers.
Those engines are pretty sensitive to spark plug condition. But its a good chance you are spot on with the TPS guess, but its a guess, as you know because it wont give a data stream, real nice, thank you chrysler.
I would suggest to hook up the DMM to the TPS and perform a sweep test. Be sure to move the throttle at a slow enough rate to allow the meters sampling rate to catch any glitch that may be present.
OR use a DSO and do a sweep with the sensor hooked up and the key on. Real time display of the Oscilliscope is a great tool.
I also have had chrysler PCMs fail and have a plethera of driveability problems, cured only by a junk yard PCM.
One other thing to consider would be dirty injectors.If they dont spray a good pattern , it can make a car run real poor. Seafoam in the fuel and some drive time will help that a lot.
Bucking and jerking can also be a cam sensor signal dropping in and out, but without a live data stream to indicate cam and crank signal being present or not, it is a crap shoot.
Fact is stranger than Fiction