Eric Groenberg

So I am going to try and explain what I had experienced over this past weekend while driving 60 to 65mph on the highway the best way possible. While cruising at a mere 60/65 mph(my max on the freeway) my Speedometer suddenly dropped(fluctuated) down to 40 mph and then spiked back up to my cruising speed(no I was not in Cruise Control either). This happened 3 times in a row, fyi. My ABS and battery light flashed on for a split second, as well as the Jeep sent out one beep(like when your tire pressure is low) during that drop/fluctuation but no engine light or codes displayed. I lost compression in the engine and speed. The engine just bogged down on me. When I pulled off the freeway onto some surface streets I noticed a big loss of power in gears 1 and 2. I had to shift quicker to maintain speed. I stopped the vehicle after about 10 more minutes of driving, waited about 20 minutes and started her back up again with no issues. I drove back home, back on the freeway making sure not to go to fast in case of any further malfunctions. All seemed normal and the same issue did not repeat itself. This happened once before about a month ago, but not in 3 in a row. I have read multiple threads that seem somewhat similar to my situation but not with the lights coming on in such. Could it be the TPS? Perhaps Spark Plugs, plug wires?
Before I start trouble shooting and blowing through money, anyone have any suggestions or similar experience to enlighten me? I currently have 96K on the odometer.

2011 JKU Sport
Manual Transmission
4.88 Gears
2.5" TeraFlex lift, 35" Patagonia M/T's

Mark Doiron

The first thing I'd do for a weird problem like that is to pull out the TIPM, visually check all the connectors, clean them up a bit with contact cleaner, and maybe add some dielectric grease. Pull the cover off the TIPM and gently push all fuses/relays down to ensure they are properly seated. I'd also check the battery connections, and especially all grounds, to ensure solid connections (more than just an ohmmeter check--look for any corrosion that may cause problems at higher current draws but easily pass an ohmmeter test). Good luck!

Eric Groenberg

Great place to start! I appreciate your input on this. As you and I both know it could be a simple solution or be like a loose thread that leads down a rabbit hole. Weekend project here I go! I will post my outcome.

karls10jk

I haven't seen TPS being near the issue that they were in the previous models if you've got a history with the TJ model. I've had weird power losses as well that showed a code for a throttle body issue that really turned out to be a bad gasket at my EGR compounded by loose bolts there that would allow excess air in and thus present as an intake issue.

But Mark nailed it- start with the battery connections and verifying you've got a good battery. These things are pretty sensitive to having a good battery.

chiapeteater

Check the connections to your battery and make sure they are tight. I had a loose ground on mine and didn't realize it and had the same thing happen to me minus the loss of power that you are talking about.