Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WK

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 09-08-2009, 05:54 PM
mzh29's Avatar
Premium Member
 
Join Date: Jun 2009
Location: Germantown, Md
Posts: 679
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 2644
mzh29 has a reputation beyond reputemzh29 has a reputation beyond reputemzh29 has a reputation beyond repute
Throttle position question

I asked about this in another thread, but got no response. Probably because it was in the wrong section, and the wrong thread. sorry guys.

While driving with my superchips data logging, I was using the throttle position sensor monitoring feature. When I floored the gas, it would only go up to about 90% for a split second and then drop down to about 70%. Can anybody tell me why that is? I checked the throttle by putting some weight on the gas with the engine turned off and the throttle plate was as open as it can be. Any ideas why the computer is reading that it's not 100% open?

Thanks.
__________________

__________________
Jeep is gone, lots of good memories, lots of turned heads. Now driving a 2013 Charger RT blacktop!
Reply With Quote
  #2  
Old 09-08-2009, 06:44 PM
Long Live the Graphite Ghost

 
Join Date: May 2009
Posts: 13,418
Thanks: 55
Thanked 132 Times in 114 Posts
Rep Power: 542630
robpp has disabled reputation
Re: Throttle position question

i dont know exact numbers Matt but I do remember seeing on the red site the SRT8 guys discussing 73% WOT on the sensor.

I dont remember the explanation but I'll go snoop around and see if I can dig it up.
__________________

__________________
Reply With Quote
  #3  
Old 09-08-2009, 06:52 PM
Long Live the Graphite Ghost

 
Join Date: May 2009
Posts: 13,418
Thanks: 55
Thanked 132 Times in 114 Posts
Rep Power: 542630
robpp has disabled reputation
Re: Throttle position question

From a post over there: I had the wrong % but point is you will never see 100%

_____________________________________
I went out and rechecked the throttle position at wide open throttle...went back to the manual and here is what it says....here are the results;

REL TPS(0-100%)- Relative Throttle Position is the normalized relative throttle position. My Jeep at WOT shows 76%

THROTTLE CMD(0-100%)- Command Throttle Actuator Control is the position of the throttle. If throttle is closed the percentage will be 0% and if wide open 100%. My Jeep at WOT shows 76%

THROTTLE POSITION(0-100%) - Absolute Throttle Position is the position the throttle is closed. The more the throttle is closed the less the percentage is shown. My Jeep at WOT shows 86%

ACC POSITION(0-100%) -Accelerator Position represents normalized distance the gas pedal is pressed. My Jeep at WOT shows 91%

So what this tells me is in fact that we are seeing about 3/4 throttle opening and in my case the pedal is pressed 91%. The book shows what the IAT sensor does and it in fact affects fuel and timing. My timing shows at WOT about 22 deg then at shifts drops to 17deg and climbs back to 22deg. Throttle never moves during shifts but one thing I did notice is that it does not move that fast from the time you floor it to the time it opens to its maximum.
_____________________________________
__________________
Reply With Quote
  #4  
Old 09-08-2009, 07:21 PM
Scottina06's Avatar
JeepGarage Founder
My Jeep: 2014 6.4L SRT8 WK2
 
Join Date: May 2009
Location: Berea, Kentucky
Posts: 49,221
Thanks: 866
Thanked 970 Times in 685 Posts
Rep Power: 7717852
Scottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond repute
Garage
Re: Throttle position question

from what I know.....no vehicle throttles at 100%
__________________
SCOTT
The HARDER you work...the LUCKIER you are!
2014 REDLINE red Jeep SRT "BLOODIED\BlackOps CFR Edition" 1 of 1
2013 JKU Wrangler 10A-stormtrooper'ed, JW Speaker and more!
Previous JEEP rides-
2013 Jeep Grand Cherokee SRT-deep cherry
2006 Jeep Grand Cherokee Laredo-inferno red



Twitter-The_Jeep_Guy
Instagram-thejeep_guy

Reply With Quote
  #5  
Old 09-08-2009, 07:26 PM
Dylans3960ccs's Avatar
Senior Member
 
Join Date: Jun 2009
Location: Alpharetta ,GA
Posts: 3,808
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5810
Dylans3960ccs has a reputation beyond reputeDylans3960ccs has a reputation beyond reputeDylans3960ccs has a reputation beyond reputeDylans3960ccs has a reputation beyond repute
Re: Throttle position question

is that just the cars with electric throttle?
__________________
Reply With Quote
  #6  
Old 09-08-2009, 07:27 PM
hemi.jon's Avatar
Member
 
Join Date: May 2009
Posts: 802
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 2793
hemi.jon has a reputation beyond reputehemi.jon has a reputation beyond reputehemi.jon has a reputation beyond repute
Re: Throttle position question

with the way the throttle blade is slanted at rest, if it opened 100% it would actually impeed the airflow. because of the new "slant" it would be on, the blade stops were it is because it is some what level and letting air move evenly above and below it.


it all makes sense in my head. i guess i could draw a picture or something
__________________
Reply With Quote
  #7  
Old 09-08-2009, 07:32 PM
Dylans3960ccs's Avatar
Senior Member
 
Join Date: Jun 2009
Location: Alpharetta ,GA
Posts: 3,808
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5810
Dylans3960ccs has a reputation beyond reputeDylans3960ccs has a reputation beyond reputeDylans3960ccs has a reputation beyond reputeDylans3960ccs has a reputation beyond repute
Re: Throttle position question

^^ it makes sense to me.
__________________
Reply With Quote
  #8  
Old 09-08-2009, 07:43 PM
ducks unlimited's Avatar
Senior Member
My Jeep: 2008 5.7L WK
 
Join Date: May 2009
Location: Warren ohio
Posts: 3,614
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5634
ducks unlimited has a reputation beyond reputeducks unlimited has a reputation beyond reputeducks unlimited has a reputation beyond reputeducks unlimited has a reputation beyond reputeducks unlimited has a reputation beyond repute
Send a message via AIM to ducks unlimited Send a message via Yahoo to ducks unlimited
Re: Throttle position question

picture time!
__________________
2010 Chevy Impala LT
Sold-2008 JGC 5.7 HEMI, 20% FRONT TINT, DUCKS UNLIMITED TINTED TAIL LIGHTS, V-LED TURNSIGNALS, REAR STROBE LIGHT, FIRST RESPONDER 24 LED LIGHTBAR ON DASH, QWIK VALVE, MOBILE 1 OIL & FILTER, 18'' CHROME CLAD RIMS, AUTO TILT MIRRORS, SMARTBEAM TECHNOLOGY
Reply With Quote
  #9  
Old 09-08-2009, 08:07 PM
mzh29's Avatar
Premium Member
 
Join Date: Jun 2009
Location: Germantown, Md
Posts: 679
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 2644
mzh29 has a reputation beyond reputemzh29 has a reputation beyond reputemzh29 has a reputation beyond repute
Re: Throttle position question

Ahhhh, I understand exactly what you're saying. Ok, thanks guys.
__________________
Jeep is gone, lots of good memories, lots of turned heads. Now driving a 2013 Charger RT blacktop!
Reply With Quote
  #10  
Old 09-08-2009, 08:21 PM
hemi.jon's Avatar
Member
 
Join Date: May 2009
Posts: 802
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 2793
hemi.jon has a reputation beyond reputehemi.jon has a reputation beyond reputehemi.jon has a reputation beyond repute
Re: Throttle position question

ok

**disclaimer, im not a mopar engineer, nor know the truth, but this is what was in my head, i do have a good understanding of how things work by just looking, so this is what i think...


im looking at the fact that if throttle position is 100% that it would be a 90 degree turn inside the throttle body. the 90 degree turn would position the plate restricting space in the TB. so if it only opened 70% then it would be in a position were it would be flat and open letting more air across top and bottom.



this is my image, probably a few errors to are hemis..goin off memory..lol...(my head is more detailed...lol)

(image is side view)
__________________
Reply With Quote
  #11  
Old 09-08-2009, 09:42 PM
mzh29's Avatar
Premium Member
 
Join Date: Jun 2009
Location: Germantown, Md
Posts: 679
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 2644
mzh29 has a reputation beyond reputemzh29 has a reputation beyond reputemzh29 has a reputation beyond repute
Re: Throttle position question

They should calibrate the throttle sensor to read 100% when max air is flowing through the throttle body!
__________________
Jeep is gone, lots of good memories, lots of turned heads. Now driving a 2013 Charger RT blacktop!
Reply With Quote
  #12  
Old 09-09-2009, 07:01 AM
Member
 
Join Date: Jun 2009
Location: Columbus,NJ
Posts: 222
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 2180
saleen032 has a reputation beyond reputesaleen032 has a reputation beyond repute
Send a message via AIM to saleen032
Re: Throttle position question

Quote:
Originally Posted by hemi.jon View Post
with the way the throttle blade is slanted at rest, if it opened 100% it would actually impeed the airflow. because of the new "slant" it would be on, the blade stops were it is because it is some what level and letting air move evenly above and below it.


it all makes sense in my head. i guess i could draw a picture or something

At 100% it would be optimum...you are thinkining degrees....just for example, if the max throttle opening was with the blade at 90 degrees in relationship to the throttle bore, then that would be its 100% opening point...just because the blade is slanted at rest, that has nothing to do with the 100% opening point....now if you start talking degrees, that is a different story.... Now in your drawing, you are thinking degrees and not percentages....which is what we are talking about....say a throttle was only designed to turn 45 degrees, if it turned the whole 45 degrees, it would be at 100%....so degrees and percentage are much different...
__________________

__________________
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Throttle Body for 5.7 tman4024 Grand Cherokee - WK 23 10-01-2012 04:09 PM
..Ported Throttle Body by FlyinRyan.. dreamer1213 Performance Modifications 46 05-09-2010 09:09 PM
Throttle stuck open help Dylans3960ccs Troubleshooting/Problems 45 08-25-2009 06:28 PM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 11:59 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community