88 4.0 auto likes to buck alittle at 30 mph,I did all the ground replacing etc.from the list of fixes posted on here but still bucking,tranny nice and clean and at the proper level.Which one to buy or could they both cause this problem

 

Sorry is a 1989 jeep,it,s not a violant bucking,just can,t seem to make up it,s mind what gear to be in

 

Idle Air Control valve is more likely to affect your jeep at idle.. TPS would be a more likely fix and they're pretty easy to test with an analog volt/ohm meter. If it seems to be 'searching' for the right gear more than 'bucking', i'd check/adjust the TV cable. Engine off, press the adjuster button and push the cable housing all the way back into the adjuster housing. Release the button and open the throttle to wide open. You should hear the adjuster 'ratchet' as it self adjusts. Test drive.

 

well that worked ,thanks