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
  #106  
Old April 9th, 2018, 17:19
randy57 randy57 is offline
NAXJA Forum User
 
Join Date: Feb 2016
Location: arizona
Posts: 28
Re: Testing Jeep O2, Oxygen sensors

What I found today:
What ever it was that took out my o2 sensor, or fouled its function, also took out my A/C compressor clutch. Or one of the replacement o2 sensors killed the compressor clutch. All the relays test good.

Maybe the ECU is shot. Anyone know of a shop here in Arizona, Phoenix area, that knows how to diagnose Jeep Renix systems?

thanks again guy's.
Reply With Quote
  #107  
Old April 10th, 2018, 17:24
randy57 randy57 is offline
NAXJA Forum User
 
Join Date: Feb 2016
Location: arizona
Posts: 28
Re: Testing Jeep O2, Oxygen sensors

I jumped my compressor clutch with jumper wires and the clutch is working, just not when turning on a/c from cab. So I'm thinking there is maybe a fuse or a short somewhere from trying to run the aftermarket o2 sensor or when maybe when I experienced the stalling which led me to it change out the o2.
Reply With Quote
  #108  
Old April 11th, 2018, 15:13
Ecomike's Avatar
Ecomike Ecomike is offline
NAXJA# 2091
 
Join Date: Dec 2006
Location: MilkyWay Galaxy
Posts: 15,064
Re: Testing Jeep O2, Oxygen sensors

Sounds like a damaged wiring harness, somewhere to me. Bad ECU Renix is supper rare, like <.01% failures in 30 years, and only failures I ever even heard of were blown injector ground diodes that kept a fuel injector from firing. I am not buying that the O2 sensor are bad, they are just completing the circuit of a failed/damaged wiring or ECU...

There should be no power at any of the four O2 sensor wires with the ignition switch off!!!!

Is the Ignition switch shorted in the off position, or the wires at the switch/connector???
__________________
Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
Reply With Quote
  #109  
Old April 11th, 2018, 16:43
randy57 randy57 is offline
NAXJA Forum User
 
Join Date: Feb 2016
Location: arizona
Posts: 28
Re: Testing Jeep O2, Oxygen sensors

The o2 sensor has 3 wires. But still there should be no power going to them with ignition off.

There has to be a short somewhere if the ECU is not suspect. Just have to figure out where somehow or another.

Thanks for your thoughts.
Reply With Quote
  #110  
Old April 16th, 2018, 13:01
Ecomike's Avatar
Ecomike Ecomike is offline
NAXJA# 2091
 
Join Date: Dec 2006
Location: MilkyWay Galaxy
Posts: 15,064
Re: Testing Jeep O2, Oxygen sensors

My first guess is the O2 heater power from the battery is stuck on, burned contacts welded closed? The spring return can not reopen the contacts

Quote:
Originally Posted by randy57 View Post
The o2 sensor has 3 wires. But still there should be no power going to them with ignition off.

There has to be a short somewhere if the ECU is not suspect. Just have to figure out where somehow or another.

Thanks for your thoughts.
__________________
Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
Reply With Quote
  #111  
Old April 16th, 2018, 15:21
randy57 randy57 is offline
NAXJA Forum User
 
Join Date: Feb 2016
Location: arizona
Posts: 28
Re: Testing Jeep O2, Oxygen sensors

Parts stores show my sensor, white body, black boot with grey, black, red wires. What they give me via the part number are actually zerconia sensors rather than the correct titania sensors. Thats why they were creating a parasitic draw, it was due to them creating their own voltage for the heater element.

Got a used titania sensor, parasitic draw gone. I think it is lazy though or partially worn out because im not getting a open/closed back and forth loop and my LTFT and STFT are always at 128... (0%).
Reply With Quote
  #112  
Old April 16th, 2018, 15:54
Ecomike's Avatar
Ecomike Ecomike is offline
NAXJA# 2091
 
Join Date: Dec 2006
Location: MilkyWay Galaxy
Posts: 15,064
Re: Testing Jeep O2, Oxygen sensors

Yah, I am not buying that theory. I bet the used sensor has an open circuit, burned out heater element in the Titania sensor, thus can not cause the parasitic draw. And thus not going closed loop... Did you try using a new Titania sensor then if the draw is there again, pull the O2 sensor relay and see if the power draw vanishes? My bet is that relay or the female socket contacts/wires are shorted across the contacts sending power to the heater wire of the O2 sensor even with the ignition off. If I am right there will be 12 volts at the O2 sensor orange wire even with the ignition switch off.

With the ignition switch off, you should be able to short all 3 wires at the O2 sensor and not have a power draw, as there should be no electrical connection between the sensor and the battery positive post to pull electrons out of the battery.

I read that the non Renix rigs in 86-? used the other sensor type, thus the reason they screwed up and gave you the wrong one I guess. Good catch!!!

Quote:
Originally Posted by randy57 View Post
Parts stores show my sensor, white body, black boot with grey, black, red wires. What they give me via the part number are actually zerconia sensors rather than the correct titania sensors. Thats why they were creating a parasitic draw, it was due to them creating their own voltage for the heater element.

Got a used titania sensor, parasitic draw gone. I think it is lazy though or partially worn out because im not getting a open/closed back and forth loop and my LTFT and STFT are always at 128... (0%).
__________________
Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
Reply With Quote
  #113  
Old April 17th, 2018, 09:44
Royal Nonesuch Royal Nonesuch is offline
NAXJA Forum User
 
Join Date: Apr 2015
Location: Pasadena, CA
Posts: 126
Re: Testing Jeep O2, Oxygen sensors

My 1988 ate a brand-new NTK 23553 sensor in the ~7 months since I had last passed smog. Voltage just stopped fluctuating and it stayed open loop. It was one of those light-gold colored, bullet looking three-wires. Not sure why, my emissions numbers were very good last test (it was installed for the test), not running rich/no HG leaks etc as far as I know. No battery drain either, for that matter. I know 02s don't usually just die, so I'm not ruling out an issue somewhere else but I haven't seen any symptoms.

Out of curiosity, I replaced it with a spare 02 that I had laying around, the older style with a ceramic insulator (I think it was a BWM or ACDelco). It's been a couple of months now and the XJ has been very happy with it - system drops into closed loop in ~10seconds, ST/LT fuel trims are good and MPG is fine. I'm interested to see how long it holds out; I know current wisdom has usually been to use NTK.
Reply With Quote
  #114  
Old April 21st, 2018, 11:43
Ecomike's Avatar
Ecomike Ecomike is offline
NAXJA# 2091
 
Join Date: Dec 2006
Location: MilkyWay Galaxy
Posts: 15,064
Re: Testing Jeep O2, Oxygen sensors

MY current wisdom has always been to use the OEM brand Bosch on Renix. Bosch invented and patented the one that was made for Renix.

Cruiser54 swears by NTK, so I find your post very interesting.

NTK was the OEM brand for 91 and up, HOs.
__________________
Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
Reply With Quote
  #115  
Old April 22nd, 2018, 00:56
randy57 randy57 is offline
NAXJA Forum User
 
Join Date: Feb 2016
Location: arizona
Posts: 28
Re: Testing Jeep O2, Oxygen sensors

It was interesting to note for me that right at the same time I was getting parasitic draw from the sensors my A/C clutch stopped engaging. Even after removing them.

I bought a bosch and Walker sensors that matched the one I had before all my troubles started, white body, perforations on tip, Hole in the end with a flat bar insided. Both caused parasitic draw.

I got 3 junk yard sensors from 88-89 renix jeeps. No parasitic draw from any of them. 2 of which I got no ohms reading. 3rd one got 3.7 ohms.

After installing the one with the 3.7 ohms reading, no parastic draw and A/C clutch now engages.

While engine is cold loop would switch open/closed, but only till it warmed up, then it stayed on open loop.

Parasitic draw is obviously caused by the sensors having a heating element. Have no idea as to why they affected my A/C clutch.
Reply With Quote
  #116  
Old April 22nd, 2018, 00:59
randy57 randy57 is offline
NAXJA Forum User
 
Join Date: Feb 2016
Location: arizona
Posts: 28
Re: Testing Jeep O2, Oxygen sensors

Also, as mentioned above, all my relays checked fine. Even replaced with new relays just in case.
Reply With Quote
  #117  
Old April 22nd, 2018, 01:10
randy57 randy57 is offline
NAXJA Forum User
 
Join Date: Feb 2016
Location: arizona
Posts: 28
Re: Testing Jeep O2, Oxygen sensors

Quote:
Originally Posted by Royal Nonesuch View Post
My 1988 ate a brand-new NTK 23553 sensor in the ~7 months since I had last passed smog. Voltage just stopped fluctuating and it stayed open loop. It was one of those light-gold colored, bullet looking three-wires. Not sure why, my emissions numbers were very good last test (it was installed for the test), not running rich/no HG leaks etc as far as I know. No battery drain either, for that matter. I know 02s don't usually just die, so I'm not ruling out an issue somewhere else but I haven't seen any symptoms.

Out of curiosity, I replaced it with a spare 02 that I had laying around, the older style with a ceramic insulator (I think it was a BWM or ACDelco). It's been a couple of months now and the XJ has been very happy with it - system drops into closed loop in ~10seconds, ST/LT fuel trims are good and MPG is fine. I'm interested to see how long it holds out; I know current wisdom has usually been to use NTK.

What were your fuel trims?
Did it loop open/closed back and forth on cold start?
Wish I could find a new o2 sensor that didn't have the pre-heating element.
Reply With Quote
  #118  
Old April 22nd, 2018, 11:33
Ecomike's Avatar
Ecomike Ecomike is offline
NAXJA# 2091
 
Join Date: Dec 2006
Location: MilkyWay Galaxy
Posts: 15,064
Re: Testing Jeep O2, Oxygen sensors

Quote:
Originally Posted by randy57 View Post
What were your fuel trims?
Did it loop open/closed back and forth on cold start?
Wish I could find a new o2 sensor that didn't have the pre-heating element.
You could disable the O2 heater by pulling the relay. If it still gets 12-14 volts the female relay socket wiring area (or nearby wiring harness) has a short, by passing the relay.
__________________
Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
Reply With Quote
  #119  
Old April 22nd, 2018, 11:40
Ecomike's Avatar
Ecomike Ecomike is offline
NAXJA# 2091
 
Join Date: Dec 2006
Location: MilkyWay Galaxy
Posts: 15,064
Re: Testing Jeep O2, Oxygen sensors

Quote:
Originally Posted by randy57 View Post
It was interesting to note for me that right at the same time I was getting parasitic draw from the sensors my A/C clutch stopped engaging. Even after removing them.

I bought a bosch and Walker sensors that matched the one I had before all my troubles started, white body, perforations on tip, Hole in the end with a flat bar insided. Both caused parasitic draw.

I got 3 junk yard sensors from 88-89 renix jeeps. No parasitic draw from any of them. 2 of which I got no ohms reading. 3rd one got 3.7 ohms.

After installing the one with the 3.7 ohms reading, no parastic draw and A/C clutch now engages.

While engine is cold loop would switch open/closed, but only till it warmed up, then it stayed on open loop.

Parasitic draw is obviously caused by the sensors having a heating element. Have no idea as to why they affected my A/C clutch.
Sounds like a defective ground, maybe in the wiring harness, or defective wiring in the harness. You need to get the wiring layouts ( regular and physical routes ) for the AC clutch power and O2 heater power and see how that is set up and related.

There is another live thread here where they are discussing NTK having the wrong O2 sensors in the Renix part number box.

My bet is the O2 heater wire got overheated and melted insulation in the harness and is causing a random, motion sensitive, partial short, parasitic draw.
__________________
Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
Reply With Quote
  #120  
Old April 22nd, 2018, 11:55
Ecomike's Avatar
Ecomike Ecomike is offline
NAXJA# 2091
 
Join Date: Dec 2006
Location: MilkyWay Galaxy
Posts: 15,064
Re: Testing Jeep O2, Oxygen sensors

Sure sounds like you still have the wrong O2 sensor, and maybe a Bad ECU now (but they can handle a lot of abuse, so lets look at the O2 sensor first)???

The Renix O2 sensor does not put out a voltage, it is a variable resistor, and the heater element is also a resistor. The ECU supplies 5.0 volts to the sensor, and the return signal wire returns the reduced voltage coming out the other side of the O2 sensor resistor to the ECU. At idle it should swing from about 1-4 volts!!!! And at 2500 rpm tighten up to 2-3 volts or tighter. The large orange wire sends battery voltage to second resistor, the heater wire-resistor). It should be about an 8 ohm resistor IIRC.

The 91-01 sensor generates its own voltage, 0-1 volts.

Put away the MT-2500 (for now) and take a volt/ohm test meter, and disconnect the O2 sensor and test the O2 sensor HARNESS ground wires, and the 12-14 volt orange wire and the 5 volt power from the ECU wire and confirm if the ECU and harness and relay, etc , going to the O2 sensor are good or not!!!

Quote:
Originally Posted by randy57 View Post
Upon trying the part store sensors (NTK and Bosch), I connected my MT2500 and they both showed a constant 4.98v output. The current sensor I have now, which is an Autolit sensor, the voltage bounces from 0.14v - 0.16v

The Autolite sensor that I have now, because the part stores sensors drained my battery, I bought on ebay because it looked like my original sensor. (ceramic with black boot on end and holes in the end that went into the exhaust). That sensor is new, it was just an older part from either a parts store or a repair shop that went out of business. And looks like it is in perfect condition.

The ebay listing showed it to be Autolite 02024 Oxygen O2 Sensor For 1987-1990 Jeep Cherokee, wrangler, Comanche. The only difference was that the connector on the autolite was a (male), connector. Wires were Grey, black and yellow. Where as my original sensor had female connector with grey, black red wires.

Looking at the 87-90 cherokee FSM, it showed that the Autolite ebay sensor was for the 2.5 liter with the yellow wire going to ignition and the grey wire going to ECU and black to ground.

Where as the FSM showed my original 4.0 sensor as having the grey to ECU, red to relay and black to ground.

Because the ebay autolite had a male plug, I replaced the it with the female plug from my original sensor. Grey to grey, black to black and red to yellow. ( I soldered the connections).

Is it possible that the o2 sensor for the 2.5 liter behaves differently than the 4.0 liter sensor?
__________________
Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
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
Oxygen sensors JCwarrior88 OEM Tech Discussion 15 March 13th, 2011 03:51
oxygen sensors and or a pcm reflash?..... moparjim1987 OEM Tech Discussion 39 June 27th, 2008 07:33
Oxygen Sensors casm OEM Tech Discussion 10 September 12th, 2005 14:17
oxygen sensors CITYBOY OEM Tech Discussion 8 November 25th, 2004 05:43
Oxygen Sensors Nick OEM Tech Discussion 7 July 7th, 2004 21:17


All times are GMT -7. The time now is 09:41.


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