There are days the RPM fluctuates 100-250 on the freeway. It does not happen every time im on the freeway but it seems to do it mostly when going 70mph and even more on cruise control going 70. any ideas? it seems electrical not mechanical but i can be wrong.

 

I would venture to say that it has something to do with your torque converter coming in and out of lockup.

Hopefully someone will chime in with a more detailed response.

 

Try replacing the throttle position sensor. Disconnect the negative battery cable before doing so. And get a good brand like Standard or OEM(Mopar). Also download the 01 service manual available in the FAQ/DIY section.

 

i replaced the TPS and the idle air control valve in hopes to fix this problem along with a idling problem. The idling problem was fixed but the freeway problem is still there. Either its something else or i got a bad TPS.

 

i used to have a toque converter problem before i got the transmission rebuilt. On the freeway rpms would fluctuate about 500. after i got the transmission and torque converter rebuilt the unlocking stopped, but then i noticed the current problem of rpms fluctuating 100-250.

 

Either the new TPS is bad as well, or the TCC solenoid in the trans wasn't the best, or..... your torque converter is having issues.

I agree, sounds a LOT like TCC engaging/disengaging. Need to find out why.

 

What brand and was the battery disconnected when you replaced them?

 

i could see why the torque converter would be causing fluctuations, but wouldn't there be much greater RPM fluctuations like i had before? around 500-800 RPMs? The torque converter wasnt new it was rebuilt so there is the possibility it is having issues. If it is the TCC, what would have to be done to test and replace it? The TPS was(i think) a BBK, i bought it at orielys. I dont remember if i disconnected the bettery or not, it was about 2 years ago.

 

My truck has the same problem but I have noticed is only when the cruise control is engaged and the temperature is below 75°

 

yeah i thought the same until it did it a few times with out cruise control