do these automatically idle up/accelerate in 4 low to climb over obstacles?

[jav_eee]

Outside of select speed control the idol is no different than any other vehicle with an automatic transmission. When you apply the torq multiplication possible with up to a 4:1…yes it will sound like it’s reving…a little.

You didn’t watch the video?? You can literally see the RPMS go up and the commanded throttle body position moving.

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[Dougstdig]

You didn’t watch the video?? You can literally see the RPMS go up and the commanded throttle body position moving.

Didn’t have a chance to…but will now.

 

[ShadowsPapa]

I have a seatbelt bypass bottle open thing (more safety issues!) in on this video but I just did it again unbuckled and it still does it. On the edge of the ramp, foot on the brake, release, it takes a moment and then throttles up on its own. You can see in this vid the top left PID is reading pedal input and the one under it on the bottom left is throttle body position. Notice how it opens it on it’s on without pedal input. Idle speed on in drive with foot on the brake and just before it idles up is 600 and change, not 800. This was from a stop going up and incline so there was no rolling up to get to those 900 (higher than the 800 you thought) that you see as it climbs. This was tough to record while making sure everything was visible and making sure I didn’t go off the ramps. I can redo the video showing an unbuckled belt as soon as the phone I use torque on charges. It died.

I wasn't buckled in at all - seat belt untouched. I didn't bother either buckling or putting it on (was having enough trouble getting into and out of 4L LOL)

 

[WILDHOBO]

And that's a different animal completely. That's controlled by moving the shift lever to manual mode on an automatic and pressing the button (If I have that correct)
It adjusts both speed and braking for a crazy-cool "cruise control" in the rocks.

Nope. Changing to manual by itself just lets you choose the tranny gear. With speed control you choose increments starting at .6mph. Trust me. I’ve actually used every feature on this thing, off road and on. I’m not speculating based on internet searches. I’ve done it.

 

[ShadowsPapa]

just before it idles up is 600 and change, not 800. This was from a stop going up and incline so there was no rolling up to get to those 900 (higher than the 800 you thought) that you see as it climbs.

The difference is similar. Yours is running ~600, and up to ~900 while mine was idling ~800 and went up to ~1000-1100.
I used the tach, not my phone, but could have either way, the tach being less accurate of course.
Mine was also not thoroughly warmed up - I drove it out, turned it around, pulled up for the test. So total run time was maybe 2 minutes - then another 2 trying to get 4L. I need to use that more often as it's really sticky.

 

[Dougstdig]

You didn’t watch the video?? You can literally see the RPMS go up and the commanded throttle body position moving.

Easy to explain…in my mind anyway.

When idling on park or neutral there is no resistance against the engine. If there were, the engine idle would reduce at the risk of stalling.

When in gear and you lift your foot off the brake, you roll forward…maintaining engine idle speed. If someone were to push against the front of the car it would either stall, stumble or increase the idle speed.

If you add the multiplication of a low speed transfer case to the mix I have to apply more pressure to the brake to keep it still. If the brakes are wet, I have to stand on the brake or pop it into neutral. I didn’t have to do this with my XJ or TJ and in my mind it’s due to my JT being a Rubicon with a lower ratio transfer case…not to mention a diesel. When you take your foot off the brake it will do what it needs to to maintain a particular idol speed. It it encounters more resistance it will idol up a touch. Kind of fluctuate.

With the off-road speed control on, it’s even more pronounced and in my opinion not smooth at all due to a constant modulation of not only the throttle, but now adding the brakes/ABS system.

So, does the idle fluctuate, yes, but in my opinion, no more than other vehicles.

 

[jav_eee]

Easy to explain…in my mind anyway.

When idling on park or neutral there is no resistance against the engine. If there were, the engine idle would reduce at the risk of stalling.

When in gear and you lift your foot off the brake, you roll forward…maintaining engine idle speed. If someone were to push against the front of the car it would either stall, stumble or increase the idle speed.

If you add the multiplication of a low speed transfer case to the mix I have to apply more pressure to the brake to keep it still. If the brakes are wet, I have to stand on the brake or pop it into neutral. I didn’t have to do this with my XJ or TJ and in my mind it’s due to my JT being a Rubicon with a lower ratio transfer case…not to mention a diesel. When you take your foot off the brake it will do what it needs to to maintain a particular idol speed. It it encounters more resistance it will idol up a touch. Kind of fluctuate.

With the off-road speed control on, it’s even more pronounced and in my opinion not smooth at all due to a constant modulation of not only the throttle, but now adding the brakes/ABS system.

So, does the idle fluctuate, yes, but in my opinion, no more than other vehicles.

I was on an incline butted up against the ramp. Stalled already. Idling at the same speed as if my foot were on the brake. It didn’t idle up WHILE my foot was on the brake in the same manner it did after I let it go.

 

[Dougstdig]

I was on an incline butted up against the ramp. Stalled already. Idling at the same speed as if my foot were on the brake. It didn’t idle up WHILE my foot was on the brake in the same manner it did after I let it go.

Interesting

 

[WILDHOBO]

Interesting

Normal behavior for a rubicon.

 

[Barnaby’sdad]

I will have to try this feature over the treacherous speed bumps at Starbucks tomorrow.

You folks take “the internets are serious business” to a whole other level.

 

[Lunentucker]

Because they aren’t lecturing about what they haven’t tried.

I typically leave the room when people who don't know something ask a question and then argue with the answers.
I do have ramps and who knows? Maybe tomorrow I'll get really curious about this. Maybe I'll go fishing.
Place your bets.

 

[ShadowsPapa]

Easy to explain…in my mind anyway.

When idling on park or neutral there is no resistance against the engine. If there were, the engine idle would reduce at the risk of stalling.

When in gear and you lift your foot off the brake, you roll forward…maintaining engine idle speed. If someone were to push against the front of the car it would either stall, stumble or increase the idle speed.

If you add the multiplication of a low speed transfer case to the mix I have to apply more pressure to the brake to keep it still. If the brakes are wet, I have to stand on the brake or pop it into neutral. I didn’t have to do this with my XJ or TJ and in my mind it’s due to my JT being a Rubicon with a lower ratio transfer case…not to mention a diesel. When you take your foot off the brake it will do what it needs to to maintain a particular idol speed. It it encounters more resistance it will idol up a touch. Kind of fluctuate.

With the off-road speed control on, it’s even more pronounced and in my opinion not smooth at all due to a constant modulation of not only the throttle, but now adding the brakes/ABS system.

So, does the idle fluctuate, yes, but in my opinion, no more than other vehicles.

Not the same thing at all. Idle speed would be idle speed while sitting.
My video shows that at that temperature, it was idling at 800 RPM in gear.
It idled at 800 RPM in gear whether moving, or when I stopped it. It then sat for about 1 second at the normal 800 RPM, then it slowly rose to 1,000 RPM, went over the bump, then backed down to 800 RPM. It's nothing to do with normal operation. It doesn't do this in 2 or 4H
It's not going to stall otherwise every time you came to a stop sign, it would stall.
Idle 800 is how it idles, either in gear or not in gear (these maintain that RPM regardless.
It has no reason at all for it to move up to 1,000 RPM - why would it when stopped it was already at 800 normal idle.

When in gear and you lift your foot off the brake, you roll forward…maintaining engine idle speed. If someone were to push against the front of the car it would either stall, stumble or increase the idle speed.

No it wouldn't stumble or stall or increase idle speed. Think of a carbureted car - you set hot curb idle in gear, foot on brake, so it idles, just for example, at 750 RPM in gear.

 

[ShadowsPapa]

Normal behavior for a rubicon.

Normal for any of them. Mine did the same. Stayed at 800 while my foot was on the brake, then increased when I let off - and it did so until it made it up the hump. Then it idled back down.
So it's not just Rubicon.
Basically, mine behaved exactly like jav_eee's did, no different.

 

[Lunentucker]

Normal for any of them. Mine did the same. Stayed at 800 while my foot was on the brake, then increased when I let off - and it did so until it made it up the hump. Then it idled back down.
So it's not just Rubicon.
Basically, mine behaved exactly like jav_eee's did, no different.

Hill holder

 

[ShadowsPapa]

Hill holder

Hill holding uses the brakes. This increased the idle to get over the hump, then reduced idle. (the nose was also pointed down, not up)

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