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Sluggishness - Stock KK feels slower than other stock KK's http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=88&t=89313	Page 1 of 1

Author:	14mustangNJ [ Tue Oct 09, 2018 9:19 pm ]
Post subject:	Sluggishness - Stock KK feels slower than other stock KK's
I'm around 84,000 miles now and the transmission doesn't necessarily shift smooth on my 2009 Liberty ,seems like it's having alot of sluggishness issues, here's where it started: I bought the hyper-tech programmer for 2008-2010 Liberty's with the 3.7. I tried the regular tune and ran it with 89 octane, initially it performed great and it took out the throttle delay/hesitation and the liberty felt peppier. It also stopped the sluggishness and delays in shifting, in particular the 40-50mph range which was always sluggish since I bought the vehicle in March. However the tune caused issues with pinging when attempting highway merging even after trying 93 octane and the biggest problem is either the engine or the transmission would "shudder" constantly when attempting to maintain 65mph, it would drive you nuts trying to maintain 65-70mph. I put back the stock tune and these problems stopped. Now back on the stock tune, my liberty feels "slower" than other stock KK's on the road. On a 45mph stretch of road, I was struggling to keep up with another stock 08-12 KK. My KK keep hesitating and having to downshift and his held speed no problem. The 35-50 range always seems sluggish and I try using tow/haul occasionally, it doesn't make much of a difference. The transmission in general really doesn't shift that smooth or consistent either, it shifts a bit hard at times and other times it's smooth? The only engine mod this Jeep has is the 4.7 TB mod, which hasn't caused any problems or trouble codes and did improve off-the-line performance. The airbox is stock and airfilter is stock, didn't notice a change in the 35-50 range with either throttle body and it's a bit more responsive than stock. ---The engine has had a tune-up (air filter, plugs changed, replaced air intake temp sensor) and runs smooth/quiet except for a random slight rough idle (almost like an uncomfortable slight chugging you can feel slightly but the rpms remain steady, not sure if it's the engine or transmission honestly) that only occurs on a random occasion if it's left sitting idling for a long time or in traffic a long-time. ----Coils were replaced before the vehicle was purchased, only replaced the plugs because I thought they were causing issues and it did the chugging prior to and after the tb switch. No issues with the cooling system either. ----No check engine light either, checked for codes and it's mainly CANBUS complaining about LED's (alot of the stock bulbs I replaced with LED's). Going to stock bulbs made no difference in driveability. ---Was a well-maintained vehicle prior to purchase with regular fluid changes, including the transmission. Any suggestions to resolve this? My father owns a 2012 Jeep Liberty with the same transmission and mileage and it shifts seamlessly, don't feel it and he doesn't have the hesitation/sluggishness I have with the transmission in my older liberty. I know the engine computers/wiring are different between the years but it seems like this Jeep has some of the typical 42RLE issues that wrangler guys complained about (05-06 had issues) when I had a wrangler, but I can't find anything in searching about transmission issues, re-flashing, TCM programming for a 2009 liberty. I would love to have the tune fix this if possible but I don't understand why it was causing issues? I thought I read somewhere specific fuses/relays have to be pulled for the hypertech tune to work properly?

Author:	lfhoward [ Wed Oct 10, 2018 12:23 am ]
Post subject:	Re: Sluggishness - Stock KK feels slower than other stock KK
This one has me stumped. You’ve done all of the things I would have suggested, like changing the plugs and doing a tune up. (I bet your plugs looked awful if you were getting pinging. I had an XJ that did that and would go through plugs very quickly. I had to go to high end fuel and change the plugs often to keep it at bay.) No use using injector cleaner since you were running 93 octane already. The next thing I thought of were your tires. If you were running bigger tires than stock, that could explain it. But I saw your other thread saying you had the original 225/75R16’s on there, which are 29” tires and should not cause a reduction in power. (I run 245/75R16’s, which are 30.5” and do sap power and mpg’s.) I have to wonder if the Hypertech tuner did not completely put back the stock tune for your transmission. Or maybe the tranny is feeling a little beat up from the performance tune. I would get the transmission fluid and filter done as my next move. It is something you can control and it is a maintenance item that is coming up anyway as you get to 90-100K on the odometer. If the fluid in there now is original, it is time. No harm done if it doesn’t work. Another idea: try going back to the 3.7 throttle body and see if that does the trick. The 4.7 may require the Hypertech tune to take advantage of it. By itself it may not help or may be the source of your power loss. Finally: (or maybe do this first before trying anything else) Unhook your battery overnight to clear the memory in the Jeep’s computer. Make it relearn your driving style from scratch. It may have some residual memory from the tuned period and may be trying to do things that it can’t anymore (like stay in a higher gear too long).

Author:	14mustangNJ [ Mon Oct 15, 2018 10:02 pm ]
Post subject:	Re: Sluggishness - Stock KK feels slower than other stock KK
Resetting the battery definitely helped, it runs smoother now and power is definitely better at least for the 350 miles or so it's been driven since the battery was left disconnected overnight. The tune was only on for about 1000 miles so hopefully it didn't cause too many problems as well. It definitely seems more responsive now, still haven't switched throttle bodies yet but it seems to be doing ok. Its a possibility the quality of gas is causing problems as it runs surprisingly well on 89 octane from a gas station I don't use regularly and my other car started throwing 02 sensor codes out of the blue two days after filling the tank on it. Definitely going to look into checking the transmission fluid and doing a fluid/filter change soon, I think that may smooth it out a bit more but it's a definite improvement now, thanks for the help!

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