does a exhaust manifold leak cause your cruise control to increase and decrease 3-5mph while set? if not, what else would cause this?

 

all cruise controls have a +or- allowance for operating conditions. Most variances are changes in road elevation or too short a time frame for the cruise to react. The JK's throttle by wire is not extremely responsive to sudden cruise control input. Yours sounds normal.

 

Yep, X2; completely normal for a JK.

My other car, an old '83 Mercedes 380SE, has a sensor in the (auto) gearbox that detects an incline/decline as it's happening & lets the cruise control computer know in advance to ease off or on the throttle well before the speed starts to decrease/increase and the computer has then to react to this. Hopefully Chrysler may adopt this 1970's German technology sometimes in the next decade or so and we can have smooth, consistent cruise control on our Wranglers.

 

AGREED --- Couple of items

#1. Already asked ,, did you change your gears?
#2. Is your speedo off, due to the larger tire size?
#3A. Did you ever have your jeep electronically calibrated via a scan tool like the AEV Conversions PRO-CAL Tool or equivalent.
#3B. If not ,,,you can update the speedo, gear change calibrtation "automatics",etc.
which may be the reason why your cruise is off, especially if you did not change your jeeps parameters. The Pro-Cal Tool lets you tell your Jeep what tires you have and other parameters, that all work together to make your jeep work like if it was stock, even with the large tires, including your ABS System.

SLIM

 

I have a 2010 Rubicon with auto trans and stock set up. I find that the cruise control is slow to respond but I feel like it is poor engine response as it will finally drop down about two "gears" and catch up to the rated speed, if I don't touch the throttle with my toe to keep the speed up. I feel the engine has too little torque to maintain the speed going up an incline with the cruise on. I was happy with the average of 21 mpg on a trip. While 21 mpg isn't great it is better than the rated 19 mpg Jeep says it will get.