Gordsram

Long time lurker and user of the info on this great site.
First time poster.

Truck is a 2004 4x4 dually with many minor improvements and upgrades to enhance its towing ability. We are retired and the truck is a dedicated tow rig. It is an automatic with just over 100,00 miles and in pristine condition.

The issue involves the cruise control and erratic cruise performance.
The situation: after a long day or more of towing ( 8 hrs highway ) disengage the cruise to slow down ( town, traffic etc), then accelerate back close to cruise speed, hit resume on the the cruise control, it will sometimes accelerate approx 3 to 4 mph past the set speed, then abruptly shut down the throttle until the rig slows to under set cruise speed, then wide open throttle until it climbs past the set point, then shut down......etc, etc. If I quickly jab the throttle and release, then it performs normally.

During " normal operation " when it works right which is most of the time, and I keep my foot in contact with the throttle ( without adding anything ) there seems to be a lot of constant peddle movement as though it is accelerating / decelerating in very small increments but still maintains the speed. I might just be **** about this and don't mean to muddy the initial issue, as this is just an observation.

My main question is could the issue be related to the TPS? ( or APPS ) I have set the voltage as per recommendations but this had no impact. The TPS is still the original.

Any thoughts and thanks in advance.

Gord