Engine Cut out at high RPM
03-13-2013 | 03:32 PM
#21
JK Jedi Master
Joined: Feb 2008
Posts: 12,882
Likes: 172
From: Maine
Until someone comes up with some tech data explaining how the JK limiter works, we are all guessing.
My guess is it controls the rpm limit through all the same programming that would come into play if you simply backed off the gas pedal.
Nothing gets shut off.
When I have tested WOT shifting, the engine reaches an rpm limit and just doesn't go any higher. It doesn't turn off and back on, sputter, or do anything other than act like I was controlling the rpm with my foot.
My guess is it controls the rpm limit through all the same programming that would come into play if you simply backed off the gas pedal.
Nothing gets shut off.
When I have tested WOT shifting, the engine reaches an rpm limit and just doesn't go any higher. It doesn't turn off and back on, sputter, or do anything other than act like I was controlling the rpm with my foot.
Last edited by ronjenx; 03-13-2013 at 03:38 PM.
03-13-2013 | 03:49 PM
#22
JK Freak
Joined: Sep 2012
Posts: 847
Likes: 1
From: Dunnellon, FL
Until someone comes up with some tech data explaining how the JK limiter works, we are all guessing.
My guess is it controls the rpm limit through all the same programming that would come into play if you simply backed off the gas pedal.
Nothing gets shut off.
When I have tested WOT shifting, the engine reaches an rpm limit and just doesn't go any higher. It doesn't turn off and back on, sputter, or do anything other than act like I was controlling the rpm with my foot.
My guess is it controls the rpm limit through all the same programming that would come into play if you simply backed off the gas pedal.
Nothing gets shut off.
When I have tested WOT shifting, the engine reaches an rpm limit and just doesn't go any higher. It doesn't turn off and back on, sputter, or do anything other than act like I was controlling the rpm with my foot.
03-13-2013 | 03:55 PM
#23
JK Freak
Joined: Sep 2012
Posts: 847
Likes: 1
From: Dunnellon, FL
Until someone comes up with some tech data explaining how the JK limiter works, we are all guessing.
My guess is it controls the rpm limit through all the same programming that would come into play if you simply backed off the gas pedal.
Nothing gets shut off.
When I have tested WOT shifting, the engine reaches an rpm limit and just doesn't go any higher. It doesn't turn off and back on, sputter, or do anything other than act like I was controlling the rpm with my foot.
My guess is it controls the rpm limit through all the same programming that would come into play if you simply backed off the gas pedal.
Nothing gets shut off.
When I have tested WOT shifting, the engine reaches an rpm limit and just doesn't go any higher. It doesn't turn off and back on, sputter, or do anything other than act like I was controlling the rpm with my foot.
http://www.bullydog.com/documents/Sp...fo%20sheet.pdf
03-13-2013 | 05:36 PM
#24
JK Enthusiast
Joined: Sep 2012
Posts: 310
Likes: 1
From: BC
Here's a better one showing how it Limits the Fuel, Not Cut the Fuel. If you meant Limit the fuel in saying cut the fuel then Mistake is all cool. But we all know that the fuel is not Cut Off
governor - YouTube
governor - YouTube
It doesn't actually stop fuel from going to the engine or kill the engine. Cut as in restrict/intermittent/limit fuel supply. On my previous vehicles you can hear and tell when the limiter would kick in and "restrict" the amount of fuel to slow the vehicle down. It obviously doesn't cut off all fuel supply to the engine, although if it did cut off the fuel supply going into the engine there would still be combustion for that Milli-second it happened. It didn't stop the fuel going to the engine for more than a fraction of a second, so you technically don't lose any power to any electronics or mechanical parts to the vehicle.Like we've established we don't actually know what's happened here except for the fact it is either fuel system/emissions (they are connected) related or computer related. Those are the most common problems associated with those vehicle systems. Next time I'll choose my wording more carefully
I also have that Bullydog programmer, but it's been sitting at my desk the last 6 months lol Should really get to putting it in the JK one of these days
Last edited by otservice; 03-13-2013 at 05:41 PM.
03-14-2013 | 07:38 AM
#25
JK Newbie
Joined: Nov 2012
Posts: 3
Likes: 0
From: Denver, Co
It would be my thought that the "cutting out" of the engine was actually the programmed "controlled decent" of the engines rpm's. I've experienced this at speed and I can attest to it being the feeling of a total cutout, high pucker factor was attained.
At the time of incident, were there any dash codes that were put off? if there was, its a script failure issues and your ECU and TIPM needs to be reflashed. If the issues was caused at a lower rpm that should be, you need to reprogram.
The JK has 62 computer control points, which does include a MAF sensor, even on the 3.8. These control points, monitor and manipulate everything, in one way or another. The monitoring of these points gives some 240000 code points. These combined in 48,263 scripts which work together in order to achieve the good, bad and indifferent operations that make the JK come alive. The derivative of all the "crunching" is some 800 possible "trouble" codes.
The simple explanation is that very few control/monitor systems on the JK are mechanical in nature. The JK basically works off of FM. Something happens, it goes to the computer where FM is created, a resulting action takes place. That can be a change in control setting or the output of a code for something that is beyond the systems FM capability.
At the time of incident, were there any dash codes that were put off? if there was, its a script failure issues and your ECU and TIPM needs to be reflashed. If the issues was caused at a lower rpm that should be, you need to reprogram.
The JK has 62 computer control points, which does include a MAF sensor, even on the 3.8. These control points, monitor and manipulate everything, in one way or another. The monitoring of these points gives some 240000 code points. These combined in 48,263 scripts which work together in order to achieve the good, bad and indifferent operations that make the JK come alive. The derivative of all the "crunching" is some 800 possible "trouble" codes.
The simple explanation is that very few control/monitor systems on the JK are mechanical in nature. The JK basically works off of FM. Something happens, it goes to the computer where FM is created, a resulting action takes place. That can be a change in control setting or the output of a code for something that is beyond the systems FM capability.
03-14-2013 | 09:05 AM
#26
JK Jedi Master
Joined: Feb 2008
Posts: 12,882
Likes: 172
From: Maine
It would be my thought that the "cutting out" of the engine was actually the programmed "controlled decent" of the engines rpm's. I've experienced this at speed and I can attest to it being the feeling of a total cutout, high pucker factor was attained.
At the time of incident, were there any dash codes that were put off? if there was, its a script failure issues and your ECU and TIPM needs to be reflashed. If the issues was caused at a lower rpm that should be, you need to reprogram.
The JK has 62 computer control points, which does include a MAF sensor, even on the 3.8. These control points, monitor and manipulate everything, in one way or another. The monitoring of these points gives some 240000 code points. These combined in 48,263 scripts which work together in order to achieve the good, bad and indifferent operations that make the JK come alive. The derivative of all the "crunching" is some 800 possible "trouble" codes.
The simple explanation is that very few control/monitor systems on the JK are mechanical in nature. The JK basically works off of FM. Something happens, it goes to the computer where FM is created, a resulting action takes place. That can be a change in control setting or the output of a code for something that is beyond the systems FM capability.
At the time of incident, were there any dash codes that were put off? if there was, its a script failure issues and your ECU and TIPM needs to be reflashed. If the issues was caused at a lower rpm that should be, you need to reprogram.
The JK has 62 computer control points, which does include a MAF sensor, even on the 3.8. These control points, monitor and manipulate everything, in one way or another. The monitoring of these points gives some 240000 code points. These combined in 48,263 scripts which work together in order to achieve the good, bad and indifferent operations that make the JK come alive. The derivative of all the "crunching" is some 800 possible "trouble" codes.
The simple explanation is that very few control/monitor systems on the JK are mechanical in nature. The JK basically works off of FM. Something happens, it goes to the computer where FM is created, a resulting action takes place. That can be a change in control setting or the output of a code for something that is beyond the systems FM capability.
Regarding the MAF sensor you mentioned, you will have to point it out to me before I'll be convinced the JK 3.8 has one.
03-14-2013 | 09:17 AM
#27
JK Freak
Joined: Sep 2012
Posts: 847
Likes: 1
From: Dunnellon, FL
This guy had a problem with his Limiter hitting a 4000 instead of the 5500, here is what they found wrong:
(yea it was the Map Sebsor vacuum line it was cracked i replaced it and it runs like brand new thanks for the input everyone .)
(yea it was the Map Sebsor vacuum line it was cracked i replaced it and it runs like brand new thanks for the input everyone .)
03-14-2013 | 09:23 AM
#29
JK Freak
Joined: Sep 2012
Posts: 847
Likes: 1
From: Dunnellon, FL
03-14-2013 | 09:27 AM
#30
JK Freak
Joined: Sep 2012
Posts: 847
Likes: 1
From: Dunnellon, FL
[h=1]MSD Ignition Offroad Rev Limiter for MSD6470 (Universal Application)[/h]
This Rev Control plugs directly into the 6-Offroad Ignition Control. It allows you to set an rpm limit that will save your engine from overrev damage in the event of driveline failure, a slick spot on the trail or missed shifts. The rpm limit is adjustable with special Weathertight RPM Modules and is supplied with 4,000, 6,000 and 8,000 rpm modules.
NOTE: Must be used with the MSD 6-Offroad Ignition
