At hiway speed the cummins been periodically raising anywhere from 100 to 400 rpm then back down on a non regular basis. The engine does this by itself. I am pretty sure my torque converter is done because I did a test and made it slip easily. Anyway today I tested the tps and got only .7 to .8v. I removed and did the open up the hole mod I have seen posted which did absolutely nothing. Opening up the holes along the edge to let the tps turn more does not work. The tps does not move in a perfect circle because it is square, so that was a waste of time. The screws never line up in the new channels. With the screws out I can turn the tps to get the 1.2 to 1.5v that may solve my problem but no way the screws would go in. I bought a new tps and installed which now gives me a .9v which is within factory spec so its getting closer. My point is the dodge service manual says to adjust the throttle lever linkage which makes sense because if I give it a little throttle I can optain the proper v as it should go up 2.2 to 2.9 at wot. I'm not sure what truck they are talking about in the genos link that everyone posts but its not my 95 12 valve because my tps holes are not slotted. I'll see if it still acts weird at hiway speed then I will know that is my tc not the tps. I guess at least I have a new tps now.

 

id say its time for a mystery switch. override the PCM for lock up

 

Where is the TPS located? I've never seen one on my truck (1994 3/4 ton 4X4) since my throttle linkage cable is connected directly to the IP.

 

According to the factory service manual the linkage should only be adjusted to the length below

 

Or maximum adjustment of 1mm. I assume there is a possiblilty it may slip that is why they are calling to adjust the cable.

The tps is mounted on the drivers side of the p pump toward the front. It screws in to the bracket that is around the spring that I guess provides resistance to the throttle cable. It has a three wire electrical connector on the bottom. I used the paperclip pushed in through the back to check voltage.

Put a couple of hundred miles on the 12 valve today and non of the weird rpm change is happening. Thank you members at DTR.