Throttle Position Sensor - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ General Discussion Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 08-06-2012, 07:42 AM   #1
Newb
 
Join Date: Aug 2012
Location: Springfield, MA
Posts: 7
Throttle Position Sensor

I apologize for being new here and posting about an issue many probably feel has been covered. I've lurked for a while and haven't found my symptoms addressed, so here I go.

My 1998 TJ Sport's engine started shaking funny last week. Sure enough, after a couple minutes the Check Engine light showed up. I parked it, and right when I put it in park the RPM's shot over 2k and stayed there. Checked the OBDII and it was P0123 (Throttle Position Sensor).

So, when the engine stopped shaking after turning the Jeep off, I turned it back on after replacing the TPS, and now the RPM's stayed at 2K when idle, and constantly cut-out while driving (for a split second or a couple it would just drift not reading that my foot was on the gas, and when it finally did it would jolt). I replaced the TPS with three different brands, same issues. I cleaned the original TPS, and when I put it back in the Jeep idled normally. Now one week has passed. I cleaned it again and I did a full system reset (did this each time I replaced it) and it does frequent cut-outs as I drove it about 15 miles. The 15 miles back home later it drove completely fine, no issues at all. Shocked, I drove it another 10, still no issues. Check engine light is still on.

I had this looked at by a master tech and he says he thinks the computer is bad and needs to be replaced. If anybody here has had something like this happen to them, I'd love to hear your story. Solutions always welcome as well.
Thanks a lot!
-Fellow Jeeper

WesternMassTJ is offline   Quote Quick Reply
Old 08-06-2012, 08:55 AM   #2
Jeeper
 
Atthehop's Avatar
 
Join Date: Jul 2008
Location: NW, NJ
Posts: 3,828
Buy a TPS from the Dealer, they are the most reliable. Many have had problems with TPS's from auto parts stores.

__________________
Retired my 94 YJ 4cyl 5spd @ 200K
Now in a 04 TJ 4cyl 5spd CV @120K+
Both as a commuter vehicle in NW, NJ
April 2012.downsized and now a 99er.
Atthehop is offline   Quote Quick Reply
Old 08-06-2012, 09:12 AM   #3
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 31,491
Images: 2
That a so-called "Master tech" would immediately jump to the recommendation you need to buy a new computer is pretty shocking. I am betting he works for a dealer.

As Atthehop says, go first for a TPS purchased from the dealer...ask for a discount, they will likely give one to you. The sensors sold by the auto parts stores are usually junk imported from China that are hit-or-miss on their quality and reliability.
__________________
Remember that having a different opinion doesn't also require one to be a jerk when expressing it.

When you have a choice, buy American.

Jerry Bransford is online now   Quote Quick Reply
Old 08-06-2012, 09:33 AM   #4
Newb
 
Join Date: Aug 2012
Location: Springfield, MA
Posts: 7
Quote:
Originally Posted by Jerry Bransford View Post
That a so-called "Master tech" would immediately jump to the recommendation you need to buy a new computer is pretty shocking. I am betting he works for a dealer.

As Atthehop says, go first for a TPS purchased from the dealer...ask for a discount, they will likely give one to you. The sensors sold by the auto parts stores are usually junk imported from China that are hit-or-miss on their quality and reliability.
Quote:
Originally Posted by Atthehop View Post
Buy a TPS from the Dealer, they are the most reliable. Many have had problems with TPS's from auto parts stores.
I really appreciate the feedback, guys! I've read this on the Forum as well, and I took the advice, but no such luck. The dealer charged $108!
I was going to buy the one on the Quadratec website, but I thought (why try a fourth)
No, the "Master Tech" worked at a reputable repair shop nearby. He didn't jump to this conclusion immediately, he took almost two and a half hours. He did say in 20 years he has only replaced one TPS. But judging by this forum and all the TPS issues, he must have only worked on one Wrangler in the past 20 years :P
I drove the Jeep on the highway today with no issues still. I am floored by how the issues are suddenly gone after one week of brutality. Check Engine light is still on though.
WesternMassTJ is offline   Quote Quick Reply
Old 08-06-2012, 03:37 PM   #5
Jeeper
 
Join Date: Feb 2012
Location: 08809
Posts: 144
Idle air control valve (IAC)?
Mctim35 is offline   Quote Quick Reply
Old 08-07-2012, 03:32 PM   #6
Newb
 
Join Date: Aug 2012
Location: Springfield, MA
Posts: 7
Quote:
Originally Posted by Mctim35 View Post
Idle air control valve (IAC)?
I tried like heck to get mine off of the Throttle Body, but it has a stripped screw. I got a special drill bit set to help remove it, but it didn't work. Next, I tried slicing a line into it to remove it with a flat-head screwdriver, but even that didn't work.

An update. It has been running fine until a little while ago I had someone clear the check engine code, and of course it came back on. However, this time the rpm's shot almost 2,400 and it drives at about 33mph without my foot on a pedal.
WesternMassTJ is offline   Quote Quick Reply
Old 08-07-2012, 08:28 PM   #7
Newb
 
Join Date: Aug 2012
Location: Springfield, MA
Posts: 7
This is not meant to be a "solution", but it made me so happy that I need to share. My check engine light turned off while I was off-roading in the woods. Must have been the computer getting wet. Happy off-roading, people.
WesternMassTJ is offline   Quote Quick Reply
Old 08-08-2012, 11:37 AM   #8
Newb
 
Join Date: Jul 2012
Posts: 2
Unhappy Iac

Where is this IAC, Idle Air Control Valve? i am having rough idle issues and i think this is the only thing i haven't changed. 97' 4.0 TJ 5 spd.
darinhebert is offline   Quote Quick Reply
Old 08-08-2012, 02:29 PM   #9
Jeeper
 
sargeparrish's Avatar
 
Join Date: Aug 2012
Posts: 42
Quote:
Originally Posted by darinhebert
Where is this IAC, Idle Air Control Valve? i am having rough idle issues and i think this is the only thing i haven't changed. 97' 4.0 TJ 5 spd.
rough idle. same issues on my 99. i had to change the ckp and the cmp twice. apparantly i got a bad new one. now it runs fine
sargeparrish is offline   Quote Quick Reply
Old 08-08-2012, 03:31 PM   #10
Jeeper
 
50Johnbob's Avatar
 
Join Date: Dec 2011
Location: Deer Park, Tx
Posts: 562
Quote:
Originally Posted by darinhebert View Post
Where is this IAC, Idle Air Control Valve? i am having rough idle issues and i think this is the only thing i haven't changed. 97' 4.0 TJ 5 spd.
Here you go,
Attached Images
 
50Johnbob is offline   Quote Quick Reply
Old 08-08-2012, 04:29 PM   #11
Newb
 
Join Date: Aug 2012
Location: Springfield, MA
Posts: 7
My problem didn't actually go away. After going the night without a check engine light and no problems, I woke up to a misty morning with my jeep covered in a layer of moisture. Sure enough, I started it (after it wouldn't catch for a few seconds) and the rpm's in idle were at about 2.3k
I drove it around and started it over and over, as the day went on it finally went to a normal idle speed. I drove it offroad and the check engine light turned off again, same place. So, could this be a cracked vacuum or something that expands during cool mornings and shrinks when it is warmed up? Any ideas?
Thank you guys, you're all very helpful!

WesternMassTJ is offline   Quote Quick Reply
Reply

Tags
throttle position sensor

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may 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




» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 12:33 AM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC