NAXJA Forums -::- North American XJ Association  

Go Back   NAXJA Forums -::- North American XJ Association > NAXJA Unibody Jeep Technical Forums > Jeep Cherokee XJ (1984 - 2001) > OEM Tech Discussion
HOME Member FAQ Sponsor Info Rules Bylaws E-Mail

OEM Tech Discussion Forum for OEM (Original Equipment) or stock XJs and MJs.

Reply
 
Thread Tools Display Modes
  #1  
Old June 5th, 2003, 11:57
rtaboada's Avatar
rtaboada rtaboada is offline
NAXJA Forum User
 
Join Date: Apr 2003
Location: La Paz, Bolivia
Posts: 31
Unhappy Throttle Position Sensor (TPS) HELP!!!!

Hello I have a XJ of the 88, How i can prove if the TPS is badly and no my CPS

Thanks
Reply With Quote
  #2  
Old June 5th, 2003, 17:41
4xBob 4xBob is offline
NAXJA Forum User
 
Join Date: May 2003
Location: Prince George, BC, Canada
Posts: 434
Can you tell us what it is doing wrong? If the CPS dies, then there is no spark. If the TPS goes, then idle usually goes up too high (at least the last two times on my 1990). If you have an automatic transmission then a bad TPS will cause some weird dhifting- on mine I notice the shift points have changed- since the TPS also sends a signal to the automatic transmission. If your 1988 XJ is bogging down and threatening to die at idle, then it is likely the EGR (exhaust gas recerculation valve). Test the EGR by pulling off the rubber line from the accumulator/pot thing to the valve heavy part, and block it with a plug (golf tee works). If that solves the low idle then it is a faulty EGR. It could be other things- can you tell us how it runs? 4xBob
Reply With Quote
  #3  
Old June 5th, 2003, 19:22
rtaboada's Avatar
rtaboada rtaboada is offline
NAXJA Forum User
 
Join Date: Apr 2003
Location: La Paz, Bolivia
Posts: 31
Yes I have problems with my CPS disconnect and connect when it does not start, but now the acceleration does not lower of 2500 this can be the CPS or this problem is only the TPS, and yes have problems of relations, is automatic.

I am live in Bolivia, and is very dificult change parts

Thanks for your help

Rodrigo
Reply With Quote
  #4  
Old June 5th, 2003, 20:05
martin's Avatar
martin martin is offline
NAXJA Forum User
 
Join Date: Mar 2003
Location: Huntsville, AL
Posts: 910
rtaboada,

At 15 years old both the CPS and TPS are close to the end of their lives. The unplugging and replugging of the CPS is the way to make a bad CPS work. I would replace the CPS first. Since you may go to high altitudes make sure you buy the High altitude CPS, the Jeep Part Number is 53005421.

There are internet sites that sell Jeep parts at a discount, I'd look at parts.com and see if you can find one of the dealers listed who will ship to Bolivia. I also found rockauto.com has parts for our XJ and they seller the better aftermarket brands.

Hope that helps you keep your XJ in parts!

Martin
Reply With Quote
  #5  
Old June 17th, 2003, 12:18
rtaboada's Avatar
rtaboada rtaboada is offline
NAXJA Forum User
 
Join Date: Apr 2003
Location: La Paz, Bolivia
Posts: 31
Thanks, buy in rockauto the TPS, and have shipping to bolivia

but delay in arriving two weeks

I can drive with disconnected TPS. ?

Thanks
Reply With Quote
  #6  
Old June 17th, 2003, 13:06
satan's Avatar
satan satan is offline
NAXJA Forum User
 
Join Date: Apr 2003
Location: Lakewood, CO USA
Posts: 327
Rodrigo,
With your automatic transmission, your TPS should have 2 connectors. You should be able to drive OK with the flat one disconnected -- the square connector provides a signal that is for the TCU (Transmission Control Unit). It would be best to leve the square one connected
Reply With Quote
  #7  
Old June 19th, 2003, 06:40
Greg Smith Greg Smith is offline
Jeep addict
 
Join Date: Mar 2003
Location: Spotsylvania, Virginia
Posts: 212
Since you have an 88 model you have the c101 connector on the bulkhead above the engine on driver's side. All the sensor wires including the tps and cps pass through this connector on the way to the computer. This connector was such a problem it was eliminated starting in the 89 model yr. Often the contacts inside this connector get dirty and corroded. Clean them all and relube the connector inside the c101 w. dielectric grease. Also check your cps with a multimeter to see if it is still good. Often the problem is just the wire harness connector for the cps near the last fuel injector. Hook a volt meter to the two wire coming from the cps w. the connector disconnected. It does not matter which wires you hook the volt meter wire to. Crank engine and if you meter shows volts fluctuating between .5 and .8 or more volts (yes less than 1 volt) your cps is usually still good and the problem is just your connectors. If the c101 clean up does not fix the problem then your cps wire harness connector is bad. Replace the connector ends (on both sides of the connector) with something else to give a better connection. Since the cps generates such low voltage any loss due to a poor connection causes problems. Good Luck. Greg
Reply With Quote
  #8  
Old June 19th, 2003, 09:45
Hawaiian Style's Avatar
Hawaiian Style Hawaiian Style is offline
NAXJA Forum User
 
Join Date: Jun 2003
Location: JAX
Posts: 428
Sounds like these guys are well on top of your problem.

My experience in layman's terms:

TPS- idle is high, transmission shift points messed up and shifts way to early or not at all.

CPS- engine starts either not at all, misses and shakes, or starts perfectly. You never know what you get when you turn the key from start to start.

EGR- EXPENSIVE TO REPLACE. I bought mine at the dealership. My wisdom there is MAKE SURE the cat. converter is ok BEFORE replacing it or you'll burn out the rubber hoses on your brand new and very expensive EGR.

My XJ is exactly the same age as yours and I've had to replace all of those things and a couple more after having the engine rebuilt. I was advised to change every sensor on the Chief which I have been in the process of doing.

Good luck!
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
4WD light off, under full throttle SV1CEC Modified Tech Discussion 22 December 14th, 2003 00:17
Help? Broken Cable on Throttle Body BobCSmith OEM Tech Discussion 5 November 24th, 2003 10:49
Stock throttle body Letterman Wanted: Private Party Only 0 November 10th, 2003 16:52
Boring my throttle body - can I use a brake hone? ZmOz Modified Tech Discussion 6 October 5th, 2003 06:48
Throttle Body Spacer xj92 Modified Tech Discussion 4 May 6th, 2003 01:18


All times are GMT -7. The time now is 16:54.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
NAXJA and NAXJA logo's Copyright NAXJA. All content/images Copyright NAXJA 1999-2014