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Discussion Starter #1
I bought my first jeep about 2 weeks ago. It's a 2dr stock 2013 freedom edition, purchased used from a dealership. It's also my first manual transmission. I have driven MT a few times in the past and I got a refresher course before buying the car, but I'm still on the low end of the learning curve. I can get myself around but its not smooth.

I have a question about the throttle... Any help or advice is much appreciated.

When I press the gas pedal as lightly as I possibly can, the jeep lurches forward and tips back a bit. When I let off the gas pedal (again as slightly as I possibly can) the reverse happens: the car feels like somebody braked hard and it tips forward. This happens after I'm in gear, already rolling forward, and revving at least 1000 RPMs. My foot is completely off the clutch pedal while this happens. If I keep my foot right around this invisible point on the gas pedal, the car will continue to randomly lurch forward and backward.

This is very noticeable in 1st gear, a little less noticeable in 2nd, and virtually non-existent in 3rd-6th.

I've tried to do some research and a lot of what I've found boils down to, "become a better driver." Of course a lot of that advice comes on high-end sports car websites, so I don't know if it applies to a JK. Obviously I'm going to keep practicing, but the throttle on the JK seems insanely sensitive.

My question: is this normal/expected for a 2013 JK? Is it operator error? Or is it something that needs to be serviced?

I just got it home from the dealership about 2 weeks ago and didn't notice this during the test drive b/c we hardly spent any time in 1st and 2nd. I noticed it immediately while trying to navigate the tight parking garage at my apartment building. It's also really noticeable in slow moving traffic where I just want to stay in first and roll very slowly.

I tried turning off Hill Start Assist to see if that was the cause, but that didn't make a difference. I read that a dirty throttle body can cause this problem but this car only has 20k miles on it. Could the throttle body really be that dirty after 20k miles?

I don't want to pay money to take it in and just have them tell me that there's no problem...
 

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Summary: Jeep is fine. It's normal. You'll get used to driving and it won't happen.

This happens in all MT vehicles (some more than others—especially if engine/trans mounts are worn). When you're in gear, the engine is directly connected to the wheels; there is no fluid coupling like most automatics (this softens the drivetrain). When you lift off the throttle, the injectors shut off and the engine essentially becomes a big brake. This causes the vehicle to decelerate.

In first gear, it can be tricky because the effect is much more prominent. You can get in kind of a feedback loop where you accelerate and lurch backward, let off the gas, then lurch forwards, hit the gas again... If you get in this situation, just clutch back in and start again.

In time, you'll learn how to drive smoothly. It's just a matter of experience.
 

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You notice the "jumping" a lot more in first and second because the gearing is so low. An extra 500 rpms makes a more noticeable and quick reaction at the wheels causing the jump forward and back. Play with the clutch a little when navigating tight quarters, obviously if you ride the clutch for long periods of time it will wear out quicker but depressing it a little to buffer throttle control is part of its purpose and won't negatively affect it as long as this isn't a constant thing. eventually you will get the muscle memory and ability the lightly apply throttle without making it jump but you'll still need the clutch a little.

Also as a side note since you are a new manual driver, when you are in neutral, don't keep the clutch pedal in. Even if you are coasting in neutral to a stop you should release the pedal to avoid unnecessary wear and tear.
 

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Yes this 100% normal and due to the lack of experience of driving a manual. A simple technique for sensitive gas pedals is to rub the side of your foot against the side of the footwell to create more resistance for your foot movement.
 

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Discussion Starter #5
Wow, thanks for all the quick replies. Definitely makes me feel better. The tip about putting your foot against the footwall makes sense. I'll try it.

Also, is it okay to start in second gear from a stop on a level surface? The owners manual says to always start in first -- so I should probably just listen -- but I've read a lot of posts by jeep owners who start frequently start in 2nd. I'm a lot smoother in 2nd for sure, but I guess a big part of that is not having good throttle control yet.
 

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I've never driven a manual jeep but I have owned a couple of manual trucks over the years. I've heard some Jeep drivers note that since the gearing is so low, they find it easier and smoother to just take off in second from a dead stop. Play around with that and see how it works for you.

Edit to add: Your last post came across while I was typing. So I see you already know about taking off in 2nd. If it works better for you, I say do it. After you have some experience and get a better feel for it you probably won't find first so challenging.
 

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Wow, thanks for all the quick replies. Definitely makes me feel better. The tip about putting your foot against the footwall makes sense. I'll try it.

Also, is it okay to start in second gear from a stop on a level surface? The owners manual says to always start in first -- so I should probably just listen -- but I've read a lot of posts by jeep owners who start frequently start in 2nd. I'm a lot smoother in 2nd for sure, but I guess a big part of that is not having good throttle control yet.
you're likely smoother in second because you're slipping the clutch more to get going in the taller gear. I always start out in first gear no matter what manual vehicle I'm driving. Get used to driving it properly before starting to play around.
 

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Agree'd, you should be able to ease the clutch out without throttle to take off, so if you find yourself adding throttle (especially if it's a lot of throttle) to take off in 2nd I'd go back to using 1st.
This works for trucks, not so well with cars, especially sports cars.
I think lots of folks come from low-lowend torque car experience and simply apply a bunch of throttle regardless... when my buddy drives my Jeep you would think he's pulling away in a 125 lb lb.ft. car with an aluminum flywheel... zoom zoom zooooooommmmmm ease away... I punch him every time!

A great way to practice, is find a parking lot and start out and stop over and over without touching the throttle. You'll thank yourself later.
 

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Discussion Starter #9
Awesome, thanks for the answers. I found a decent parking lot and relatively low traffic neighborhood nearby that has plenty of room to practice both flat and inclined starts.
 

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I've owned manual transmission vehicles off and on for a long time. The Wrangler is an easy manual to drive, but relatively difficult to drive smoothly.

The long throws of the transmission and driveline slop really makes for some klanker shifts. I'd recommend starting in first, you're probably wearing out the clutch starting in 2nd.
 

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I felt the same way a couple months ago lol. This was my first mt vehicle. I have slowly gotten the hang of smooth starts. It all takes time and figuring out the right amount of gas I guess
 

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I've owned manual transmission vehicles off and on for a long time. The Wrangler is an easy manual to drive, but relatively difficult to drive smoothly.
Agree'd, I have owned nothing but manual transmission vehicles since 1984, and I found the JK a pita to get used to. The soft rubber bushings in the control arms, combined with the worst throttle ever (hate hate hate drive by wire) and the long throws... I really wish there was a simple way to control the throttle body by cable, and really wish Hurst would make a proper shifter.
I'm used to it now, but that is not to say I am a big fan. Still prefer it over an auto any day.
 

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At a complete stop I always start in first, in second if I'm moving a little.

I never touch the throttle until it starts moving. Unless you're dumping the clutch, the JK is hard to stall. The drive by wire doesn't bother me any more, I guess I got used to it. I see no difference anymore with drive by cable.
 

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Drive by wire sucks. I've owned a lot of MT vehicles, and the my 2012 JK is the most difficult to learn to drive smoothly. It'll take some time and patience.

Oh...and disable Hill Start Assist. I was hesitant to do so, but once I did, I've never looked back. Makes starts so much easier - regardless of what gear.
 

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At first I thought about starting in second. It was not v long at all and I realized that would lead to a short clutch life.

Once you get the hang of it it'll be easy.

My brother wanted me to take his son out in it and teach him how to use a manual. I just lol, "you got $500 deposit for the clutch I asked". Which made me think about letting out the peddle and feeding it gas.

I realized on a flat surface the clutch can be let out fully without giving it any gas at all.
That is creeping at it's slowest. Just barely giving it gas and it goes. Be deliberate on the gas, it's a high torque vehicle, it's a heavy vehicle.
 

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As others have mentioned, the gas is very light switch on/off because of the drive by wire. Just keep it at, it sounds like you're on your way.

I'm used to my Jeep now.
 

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I will generally not be driving it around under 1500 or so in first gear. When I'm starting off I'm at 1500 by the time the clutch is fully engaged and when I crawl to a stop I would normally disengage the clutch.
 

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To keep mine from lurching forward when I have to let off the gas quickly, I pull it out of gear without pressing the clutch. This may seem foreign to you at first and everything in you will tell you not to do it, but if you time it right, there will be little to no resistance when pulling it out of gear as if you did push the clutch in. Try it out, but never pull hard. If you feel the need to, your timing is off and you will grind the gears pulling it out. Good luck! It's not fun learning but once you know it you'll know it for life
 

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To be honest, I didn't realize the JK was gas by wire until someone mentioned it. Feels the same as many past sticks. Even my wife, which has no hand eye coordination, drove it fine from the first time. If anything, it's easier since the engine it's hard to stall. Another thing I like is that it holds RPMs while shifting and making your shifts smoother. Not sure what is meant by on/off switch. To me, they are all the same whether carb or a cable to the TB in a EFI. It's idling until you rev it up.
 

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Do the "Throttle Calibration" technique (search on the forum) and it may help solve some of the throttle jumpiness. I have an Auto and it even helped with that. It's very easy to do and takes about 5min. You WILL notice a difference in your throttle response.

Here:
Try this


Throttle Calibration
Throttle calibration can substantially improve throttle responsiveness over "factory standard." Many people notice what appears to be sluggish throttle response or a "dead area" at initial accelerator depression. Throttle calibration can take care of these.
1) Insert ignition key and turn to "ON" (not start).
2) Wait for all idiot lights to go out. Check Engine Light may remain on.
3) Slowly depress the accelerator pedal all the way to the floor.
4) Slowly release the accelerator pedal until it's all the way back up.
5) Turn the ignition key to "OFF".
6) Start the engine.
 
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