Skipping and misfires

[omega_rugal]

i think my MAP is bad, i get the high idle starting sometimes... is tehera way to service it or must replaced?

[88whitemanche]

 

If you haven't already, switch out your cables for bigger gage cables or just change them out because they are old...

I went from a 60amp to 100amp on my truck and melted the wires, luckily I caught it in time and not burn down my truck...

Pics of wires....

Damn, even without any extra load (lights, winch, stereo, etc)?

I was trying to get a set of pre-made wires but it's looking like I'll be buying a hydraulic crimper and making my own. Anyone have gauges/ lengths needed by chance?

Sent from my SM-G930T using Tapatalk

Nope just plain Jane simple at the time, no radio,no lights, just either the cables were old and cruddy or just couldn't handle the amperage anymore

[cruiser54]

Need high quality cables pre-made?

 

If you want to upgrade your ground and battery cables with custom made parts, contact Neal at Mean Lemons Sweet Cables. Meanlemons@gmail.com

[Tex06]

Need high quality cables pre-made?

 

If you want to upgrade your ground and battery cables with custom made parts, contact Neal at Mean Lemons Sweet Cables. Meanlemons@gmail.com

Thanks Cruiser!

 

Sent from my SM-G930T using Tapatalk

[cruiser54]

 

Need high quality cables pre-made?

 

If you want to upgrade your ground and battery cables with custom made parts, contact Neal at Mean Lemons Sweet Cables. Meanlemons@gmail.com

Thanks Cruiser!

 

Sent from my SM-G930T using Tapatalk

 

You bet. He makes great stuff, and he just traded his XJ for 2 Comanches. One Renix and one HO!!!!!

[HOrnbrod]

Does this person have a web site? Location? Member of another forum?

 

Does he use lemon batteries?   :yes:

[cruiser54]

Does this person have a web site? Location? Member of another forum?

 

Does he use lemon batteries?   :yes:

He's a moderator on Cherokee Forum.

 

He just bought a house and is packing up right now for the move. He will have a website in the future. 

 

Mean Lemons is a jumble of the letters of his first and last name.....

[cruiser54]

And now he's joined Comanche Club.

 

There goes the neighborhood..................as Mean Lemons

[MeanLemons]

-Indeed, as Pete here mentioned. I traded my 98 XJ for two MJs; 88 Pioneer with 4.0/auto 2wd and a 91 Eliminator with 4.0/ax-15 2wd.

 

Mean Lemons is an anagram of my first and last name. My name is Neal E. I live in west Chester, Pennsylvania.

 

I'm a moderator on CherokeeForum and a member of NAXJA & CherokeeTalk as well. I have had multiple XJs and WJs. Although right now I'm down to a XJ (my crawler) and now two MJs. My username on all those other forums are XJwonders. The reason why I didn't continue the practice of using that username because it wouldn't fit well in a forum specifically for MJs. Ha.

 

I can be contacted at MeanLemons@gmail.com for speedy responses. (I hope I'm not breaking any rules by posting my email here regarding cables, but it was already mentioned here before I signed up). Unfortunately I don't have a website at the moment, but that's something I would like to look into in the future eventually.

 

I signed up here so I can learn more about the MJs... Sure the other forums have a section devoted to the Comanches but I figured why not join a MJ specific forum as well.

 

Looking forward to learning/meeting some of u guys here,

 

Cheers, Neal

[HOrnbrod]

Welcome aboard.  :thumbsup:

 

Regarding your cable sets, you might want to post details in the Classified / Vendors fourm. Pics and prices would be good too if possible. 

[Tanner]

Indeed, I would be interested.

[cruiser54]

Indeed, I would be interested.

http://comancheclub.com/topic/51435-upgraded-battery-cables/

[Tex06]

 

Most all of the HO sensors use a 5VDC reference voltage. This voltage is generated by the ECU and the tolerance is tight. One thing you should try is disconnect the 60-pin connector from the ecu and check for recessed pins, then clean both sides up carefully with a good electrical contact cleaner. Do not use dielectric grease when reconnecting. This usually brings the sensor 5V reference voltage back up to specs by cleaning up any corrosion (resistance) from the pins. 

 

 

Pulled my 60-pin apart yesterday.  Sure enough, white corrosion on several of the pins.  I wire brushed them as best I could and cleaned with QD cleaner (electronics cleaner).  Voltage at the TPS is now up to 4.94VDC, so I'm much closer.  When I check my readings from the TPS though, they're not smooth at WOT, sometimes I get the full 4.94, but a lot of times it's only 3.9~4.00 VDC.  As soon as I get my dashboard put back together for this dumb vacuum line (http://comancheclub.com/topic/51514-vacuum-hose/ ) I'll take it for a test drive and see what's up.  I have been getting Engine Code 24 (TPS signal bad essentially) so I'm wondering if it was the reference voltage or the signal voltage that was throwing the code.

 

You wouldn't happen to know the tolerance for the 5VDC from the ECU would ya?

[HOrnbrod]

If a sensor's reference voltage is low, the sensor output voltage will also be proportionally low. That's why you always check the reference voltage first. I'm pretty sure the ECU 5VDC reference voltage tolerance is ± .2V.

 

Testing the OBD1 TPS

 

The throttle position sensor is connected to the throttle shaft on the throttle body. It sends throttle valve angle information to the PCM. The PCM uses this information to determine how much fuel the engine needs. The TPS is really just a simple potentiometer with one end connected to 5 volts from the PCM and the other to ground. A third wire is connected to the PCM. As you move the accelerator pedal with your foot, the output of the TPS changes. At a closed throttle position, the output of the TPS is low, about a half a volt. As the throttle valve opens, the output increases so that, at wide open throttle, the output voltage should be above 3.9 volts. Testing can be performed with an electrical meter. Analog meter is best. You are looking for a smooth sweep of voltage throughout the entire throttle band. While slowly opening and closing the throttle, take note to the movement of the voltmeter needle. There should be a direct relationship between the needle motion to the motion of the throttle. If at anytime the needle moves abruptly or inconsistently with the movement of the throttle, the TPS is bad

You should have 5 volts going into the TPS. At idle, TPS output voltage must be greater than 200 millivolts. At wide open throttle (WOT), TPS output voltage must be less than 4.8 volts.. The best is to use an analog meter (not digital) to see if the transition from idle to WOT is smooth with no dead spots. With your meter set for volts, put the black probe on a good ground like your negative battery terminal. With the key on, engine not running, test with the red probe of your meter (install a paper clip into the back of the plug of the TPS) to see which wire has the 5 volts. One of the other wires should show .26V (or so). The other wire will be the ground and should show no voltage. Move the throttle and look for smooth meter response up to the 4.49 at WOT.

Perform the test procedure again and wiggle and/or tap on the TPS while you watch the meter. If you notice any flat spots or abrupt changes in the meter readings, replace the TPS.

The TPS is sensitive to heat, moisture and vibration leading to the failure of some units. The sensor is a sealed unit and cannot be repaired only replaced. A TPS may fail gradually leading to a number of symptoms which can include one or more of the following: -

NOTE: The throttle position sensor is also DIRECTLY involved with transmission shifting characteristics! It should be verified early in the troubleshooting process, when a transmission issue is suspected!

• Poor idle control: The TPS is used by the ECU to determine if the throttle is closed and the car should be using the Idle Air Control Valve exclusively for idle control. A fault TPS sensor can confuse the ECU causing the idle to be erratic or "hunting".
• High Idle Speed: The TPS may report faulty values causing the engine idle speed to be increased above normal. This is normally found in conjunction with a slow engine return to idle speed symptom.
• Slow engine return to idle: A failing TPS can report the minimum throttle position values incorrectly which can stop the engine entering idle mode when the throttle is closed. Normally when the throttle is closed the engine fuel injectors will be deactivated until a defined engine RPM speed is reached and the engine brought smoothly to idle speed. When failing a TPS will not report the throttle closed and fueling will continue causing the engine to return to idle very slowly.
• Engine Hesitation on Throttle Application: The TPS is also used by the ECU to determine if the driver has applied the throttle quicker than the Manifold Air Pressure sensor can read. The fueling is adjusted acordingly to cope with the sudden increase in air volume, however a faulty sensor can cause the ECU to ignore this data and the engine will "hesitate" when applying the throttle. In extreme cases with the engine at idle, a sudden application of full throttle can stall the engine.
• Engine Misfire: A fault TPS can report values outside the deined acceptable range causing the ECU to incorrectly fuel the engine. This is noticable as a slight misfire and can trigger the misfire detection software and/or Malfunction Indicator Lamp (MIL) light on the dashboard. Extreme cases can cause excessing misfires resulting in one or more cylinders being shut down to prevent engine and catalytic converter damage.

 

[HellCreek]

Hi, Tex,

 

I realize this is an old thread, but did you ever solve this problem?  I am having surging/stumbling issues with my son's '91 XJ Cherokee Laredo with the 4.0 engine.  I have run the codes, and I get 12 and 55.  I have checked the vacuum lines, and all are good.  I replaced the battery cables, fuel pump and filter, fuel rail and pressure regulator, checked and cleaned all of the ground attachments (including the left tail light) and replaced the temperature sender in the thermostat housing. I also  changed the ignition switch and the tumbler.  Like all of the PITA issues, this is very intermittent, rearing its ugly head  at the worst possible times, like in heavy traffic.  When it occurs, the engine will stumble at any rpm, not just at idle.  The car starts normally and runs smoothly (when it is not experiencing the problem).  Since you seem to have had the same problem, I was wondering if you discovered and corrected the cause.

 

Thanks,

Tom

[HellCreek]

Bump

 

[jdog]

might start a new thread instead of bumping a 4 year old one, Don has passed and Tex hasn't been on in a couple years

[HellCreek]

Hi, Jason,

 

Thank you for responding. 

 

I am truly saddened to learn of Don's passing.  He was a great guy and will be sorely missed.  How long ago did this happen?

 

As to the age of the thread, when do they become obsolete?  I was under the impression that, as long as an issue is still relevant (as in my case) and is still unresolved, it is current.  If this is incorrect, why is it still searchable?  I mean no disrespect, but I am having this problem and am in need of a solution, and was wondering if anyone else had this issue and had resolved it.

 

Thanks,

Tom

 

[Pete M]

Don passed about a year ago.  

 

It's not so much about obsolescence, it's about human nature.  It always seems that fewer guys will look at an old thread.    when searching for a solution, the more eyeballs that see it the better the chances that you'll get a guy that knows the answer.   I've had plenty of times that a bump like yours went unanswered but then I split it off into its own thread and gave it a descriptive title and suddenly people responded. 

[WahooSteeler]

7 minutes ago, HellCreek said:

Hi, Jason,

 

Thank you for responding. 

 

I am truly saddened to learn of Don's passing.  He was a great guy and will be sorely missed.  How long ago did this happen?

 

As to the age of the thread, when do they become obsolete?  I was under the impression that, as long as an issue is still relevant (as in my case) and is still unresolved, it is current.  If this is incorrect, why is it still searchable?  I mean no disrespect, but I am having this problem and am in need of a solution, and was wondering if anyone else had this issue and had resolved it.

 

Thanks,

Tom

 

 

Agreed. People complain about redundant questions on a new thread and tell you to use the search feature, then when you do other people ride you about bringing up an old thread. Damned if you do, damned if you don't. I recently had stalling issues and used the search to find LOTS of threads on the issue, as is often the case, and was fortunate to find one that addressed my exact symptoms, but the source of my problem and the fix was different than others in that thread. So instead of starting another thread I just posted to the old one to "update" it, IMO. I'd personally rather only have to sort through a few ongoing threads, even if it is pages long, than to have to sort through 25 threads (and that's no exaggeration sometimes) related to my problem. 

 

jdog, since you offered no input to Tom's issue, I see no reason for you to comment at all that he added to an old thread. Doesn't affect you at all. 

[Pete M]

7 minutes ago, WahooSteeler said:

jdog, since you offered no input to Tom's issue, I see no reason for you to comment at all that he added to an old thread. Doesn't affect you at all. 

 

 

I feel it was important that someone mention that the 2 key contributors of that thread will not be responding.  If Jason didn't do it, I would have. 

[WahooSteeler]

20 minutes ago, Pete M said:

 

 

I feel it was important that someone mention that the 2 key contributors of that thread will not be responding.  If Jason didn't do it, I would have. 

 

Fair and valid point Pete. Just didn't need the extra comment about adding on to an old thread. 

[jdog]

my apologies, I only did it as it seemed as tho no one wanted to help. But if we want to continue on this thread that is no issue as well. most people will not respond when it is directed at someone that is not them

ok here we go 12 and 55 are permanent codes, they will always pull up in the system, 12 is loss of battery or battery disconnected, and 55 is end of codes. the way it is being described it is a heat issue, so, other then throwing parts at it have you done any tests? What does the temp gauge say? last time a tune up was done (plugs wires filter)?

[HellCreek]

5 minutes ago, WahooSteeler said:

 

Fair and valid point Pete. Just didn't need the extra comment about adding on to an old thread. 

Hi, Guys,

 

Thanks for your replies.  I'm happy to see that both of you are still around, and I agree with both of you.  Old posts should not be canned as they are still relevant as long as the underlying issues remain.  I do think and wish that, when issues are resolved, the solutions should be posted, so that others would know what finally fixed the problem.  Maybe then old posts would not have to be resurrected, but unanswered issues leave a void that to me must be resolved, especially if I am having the same problem.

 

Thanks, Pete for letting me know about Don.  I always wanted to go visit with him, since he was only around 100 miles from me.  Now I will never get the chance.

 

Thanks,

Tom

[Pete M]

10 minutes ago, HellCreek said:

Thanks, Pete for letting me know about Don.  I always wanted to go visit with him, since he was only around 100 miles from me.  Now I will never get the chance.

 

yeah, that realization hit me kinda hard last year.  He was my friend for nearly 2 decades and I never shook his hand. 

 

and so I've made it a point to visit as many of my fellow CC members as I can!  Even made a 4k mile trip last fall and met 20 or so members along the way.