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General Forums => The Mess Hall => Topic started by: little97tj on May 20, 2009, 05:26:45 AM
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:brick:
Everytime I start my jeep it has a bad hesitation untill it warms up, It will actually run fine untill a curtain point then the motor will start to stuble sounds like it has a huge cam at idea "kind of cool sounding" anyhow if you try to drive it at this point it has no power and falls on its face. On the other hand if you hold it to the flooor it will drive threw it and then be fine.
I've been dealing with this issue for a while but jeep only gets off roaded for the most part, I switched to a 4.0 throtle body at one point thinking it might help but probem remained the same. I left all the sensors on the 4.0 throttle body like i said problem was the same no better of no worse
Jeep has 105k on it, was thinking Id try and sort this out before the holiday weekend... anyone else seen this problem? I seen other post that sounded the same but no solutions
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missfire, dumping fuel then clears up nd drives fine
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:thumb:
That would be the animal
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I'm having a similar issue, but here's a little back story. When I had about 20,000 miles on my Jeep, it developed a bad stalling/loss of power, not just at idle but also randomly while driving. It wound up getting so bad that it just had zero power all the time and I finally got my dealership to take a look at it. It wound up being that the Cat was clogged. As soon as they replaced it, the problem went away for about 5,000 miles then it kinda started again but I got a check engine light this time. This time I had a bad spark plug, I replaced all the plugs and wires and it ran better then it ever did. Now i have around 47,000 miles and this whole thing is starting again, but this time there is no check engine light and plenty of backpressure in the exhaust so it's not the cat, are my plugs just bad again, even though I put Iridium plugs in last time?
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I have read this thread over and over again and I havent gotten a good conclusion. I also have a stumble when cold but can power through it until it warms up. Not too big of a deal, but would be nice if it wasnt there. Anyway, I have the hesitation or stumbling at around 2300 - 2800 RPM. It is sporadic and at times feels like it stalled when I am on the freeway but it stays alive. That doesnt happen to often, but I am concerned about the stumbling around this RPM range. I tested the TPS and it tested out fine. When I did the 4.0 TB conversion, the AIS was real cruddy and I cleaned it off but never done that before so I didnt want to spin it around and mess anything up. Put it all together with the old 2.5 AIS housing and its great. throttle response is much quicker. Can anyone help with the stumbling problem? I was about to unplug the O2 and see if that helps or it could be something else because after cleaning the AIS, my choke dosent stay up for more than 2-3 seconds in the morning. Vacuum leak? Dont get it. Thanks.
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you might want to check the temp sensor for the PCM, that can cause the idle to be too low at cold and not get enough fuel either - can't say it's 100% that but give it a shot.
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Ok, I was able to narrow the REAL bad stutter area. At 2800 RPM and the RPMs drop all of a sudden to about 1900 or so, like a hickup. But I can do it every time at that RPM range. Other than that REAL bad spot, it does it from around 2200 RPMs to 2800 here and there but not too bad, but still annoying. No codes were pulled (accept the Ac code of course). I thought it was the TPS as my 4Runner (auto) had the shifting between 3-4-5 back and fourth, but mostly 4-5 on the freeway. I replaced it and it helped quite a bit, but still did it every once in a while. But I pulled the TPS on the Jeep and it tested out fine. Also, when I got the 4.0 TB I took out all the sensors. The TPS from the 4.0, will it work on the 2.5? There is a #1 on the 2.5 and a #2 I believe on the 4.0 TB near the part number. They both tested fine, but can I use the TPS from the 4.0 and see if that helps before I buy a new TPS? Or do I need to look somewhere else for the solution?
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Ok, I was able to narrow the REAL bad stutter area. At 2800 RPM and the RPMs drop all of a sudden to about 1900 or so, like a hickup. But I can do it every time at that RPM range. Other than that REAL bad spot, it does it from around 2200 RPMs to 2800 here and there but not too bad, but still annoying. No codes were pulled (accept the Ac code of course). I thought it was the TPS as my 4Runner (auto) had the shifting between 3-4-5 back and fourth, but mostly 4-5 on the freeway. I replaced it and it helped quite a bit, but still did it every once in a while. But I pulled the TPS on the Jeep and it tested out fine. Also, when I got the 4.0 TB I took out all the sensors. The TPS from the 4.0, will it work on the 2.5? There is a #1 on the 2.5 and a #2 I believe on the 4.0 TB near the part number. They both tested fine, but can I use the TPS from the 4.0 and see if that helps before I buy a new TPS? Or do I need to look somewhere else for the solution?
you can't use the 4.0 tps, P/Ns are different so it will give different info to the PCM. Related to no high idle when cold most obvious can be the IAC (also known as AIS) or the temp sensor that i mentioned before. For the hesitation at a specific RPM (and this is assuming that is not at a specific TPS position, in which case would point to the TPS) - could be ignition/spark related - i would inspect the distrib cap/rotor, the wires and plugs, hopefully is one of those - If not could be crank sensor, cam sensor, MAP or even TPS but would be hard to narrow down unless you have a way to "certify" each one individually.
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I think I am going to just get another TPS and see if that helps. That seems to be the direction I am leaning and it makes the most sense. If it doesnt work, oh well, its not hard to replace and I can just return it. Since it IS at a specific RPM range, (now i think it is at 2500 RPM) its got to be the TPS. I will also try to replace the AIS and report my findings.
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This is confusing me. Originally the "bad spot" was around 2800 RPM and then lowered to 2500 RPM and now it seems like it may have either moved to 2200 RPM and/or the "hick-up" has stopped. Now it just has a slight rough spot. I don't get it. Do you think this has anything to do with the 4.0l throttle body and spacer I recently put on? Again, I noticed that the TPS, when I took it off the 2.5 and put it on the 4.0 it was a bit dirty, but I didnt see what good a cleaning would do to it since it is pretty much a sealed component, so i left it alone. The AIS was real nasty and I just whiped it down with a rag and carb cleaner. I didnt see any dirt/grime that could have come loose from the AIS to mess with the system but I didnt really clean the inside of the AIS housing from the 2.5 when I swapped it all. So far it seems like the RPM drop has been eliminated for some reason but I can still feel a rough spot around 2200 to 2500 RPM, but it is very hard to feel since the thing gets blown around in the wind so easily. Any ideas? Thanks.
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When I put the 4.0 TB on my YJ the TPS failed, then just so the jeep gods could
really laugh, I got a bad one in the box :brick: :brick:
The 3rd time was the charm, I HIGHLY recommend spending the extra dough on
the one from NAPA not Autozone.
If you saw them both taken apart its apparent that one is better quality.....
Dave
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So were you having the stumbling effect that I am having now? I only had a TPS go bad in a 4Runner and it was an automatic so it would shift erratically. So I wasnt too sure about a TPS in a 5 speed.
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It would cough and buck, power would go away, sometime get a little tail pipe pop...
sometimes you could drive through it by flooring the pedal fast.
I finally decided it was the TPS because there was a spot that if
I backed down real slow under load it would stumble just a tad.
It was way worse on the cold engine.
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Ok, replaced the TPS and it still has the same effects. I guess I need to try a few other sensors and see if that helps. Keep doing that until the stumbling stops. Again, its mostly a slight stumble. Almost feels like when you get a strong headwind hitting you, but its not that for sure. Its not like the bucking you'd get if you were running out of gas (know that feeling too well). I need to go back in this thread and look for the other culprit sensors. I think they were, AIS, O2, crank position and temp sensor right?
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Did you ever pull codes on it? I would do that at least before replacing random sensors.
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Yes, there were no codes. (Just the power steering code of course)
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I mean the air conditioning code.
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The hesitation or what I would now call a "rough spot" (as it runs a little rough) is between 2200 and 2800 RPM. No longer does it drop significantly in RPMs as it did at the 4.0 tb install, but still has the rough spot. And after replacing the TPS, it still remains. I am going to just rule out the cheap stuff, as I need to finish the tune up anyway, and replace the cap/rotor/wires. They all looked fine but you never know. Then I thinj the MAP sensor may be the next one to check. Based on what it does, that makes the most sense to me if the tune up doesnt fix it. Does anyone think its distributor related? Hope not.
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Ok, replaced the TPS and it still has the same effects. I guess I need to try a few other sensors and see if that helps. Keep doing that until the stumbling stops. Again, its mostly a slight stumble. Almost feels like when you get a strong headwind hitting you, but its not that for sure. Its not like the bucking you'd get if you were running out of gas (know that feeling too well). I need to go back in this thread and look for the other culprit sensors. I think they were, AIS, O2, crank position and temp sensor right?
AIS won't make a difference there, all the other could. btw, there is also quite a bit of difference between a "slight stumble" and "bad hesitation". I would check the spark plugs, wires, distributor cap and rotor as well since it could be spark related too (as a matter of fact start from there since checking those won't cost any money)
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Replaced cap, rotor, plugs and TPS. It seems that the stumble or rough spot has reduced slightly but I think its still there. I have been trying to reproduce the effect and it almost seems to me like the gas pedal needs to be let off just slightly enough to not speed up. Just enough to keep it at the right speed/RPM range. It also seems to me like it happens only when the shift light comes on. Now, this may be a coincidence but the shift light will also come on when it feels the gas pedal push down and it is at the right RPM range to recommend a shift. Now it also comes on what seems to be like a bit early (around 2200 RPM) and can stay on until I go over 3000 RPM. Does anyone know what the standard "shift time" is on these things? Does everyone elses come on at that time? I dont know. Its a bit weird. Non the less, I still feel the rough spot, but now I can pinpoint it more to an ascending motion (if that makes sense). Because If I hit the gas, it goes away, well, it seems that way.
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Replaced cap, rotor, plugs and TPS. It seems that the stumble or rough spot has reduced slightly but I think its still there. I have been trying to reproduce the effect and it almost seems to me like the gas pedal needs to be let off just slightly enough to not speed up. Just enough to keep it at the right speed/RPM range. It also seems to me like it happens only when the shift light comes on. Now, this may be a coincidence but the shift light will also come on when it feels the gas pedal push down and it is at the right RPM range to recommend a shift. Now it also comes on what seems to be like a bit early (around 2200 RPM) and can stay on until I go over 3000 RPM. Does anyone know what the standard "shift time" is on these things? Does everyone elses come on at that time? I dont know. Its a bit weird. Non the less, I still feel the rough spot, but now I can pinpoint it more to an ascending motion (if that makes sense). Because If I hit the gas, it goes away, well, it seems that way.
what happens if you try to reproduce that with the vehicle stopped (just using your throttle) - can you feel the engine vibrating/shaking at a certain rpm? also, did you change your spark plug and coil wires (since you replaced everything else).
Can't really understand what the symptom is but guessing by what you describe that you have some sort of interruption like all of a sudden 1 cyl would stop working at a certain rpm (like a misfire of some sort) and which goes away once you start accelerating - is that what the behavior is?
my shift light was never correct, but it is most likely because i had larger than stock tires with stock r&p ratio in my axles - so i quit paying attention to it - i wouldn't use that for any type of diagnosis.
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Yes, I replaced cap, rotor, wires, plugs and TPS. And like I said before, that drop in RPM I was having at 2500 RPM has stopped, but I am left with the rough running area between 2200 and 2700 RPM. Coincidently that is usually also when the shift light is on. I have not tried to reproduce the symptoms while sitting still yet. I think its easier to feel the stumbling sensation while driving that trying to feel the motor move when sitting still, but I will try it anyway. The best way for me to describe the "rough running spot" is that it feels like I am running out of gas, but on a much lighter scale. The stuttering is like a misfire. Like I need a tune-up. But that has already been done. Sorry I am not able to describe this to you in greater detail. I wish I could record it but its the feeling that you get, nothing that you could see.
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Yes, I replaced cap, rotor, wires, plugs and TPS. And like I said before, that drop in RPM I was having at 2500 RPM has stopped, but I am left with the rough running area between 2200 and 2700 RPM. Coincidently that is usually also when the shift light is on. I have not tried to reproduce the symptoms while sitting still yet. I think its easier to feel the stumbling sensation while driving that trying to feel the motor move when sitting still, but I will try it anyway. The best way for me to describe the "rough running spot" is that it feels like I am running out of gas, but on a much lighter scale. The stuttering is like a misfire. Like I need a tune-up. But that has already been done. Sorry I am not able to describe this to you in greater detail. I wish I could record it but its the feeling that you get, nothing that you could see.
well, let us know if you get some sort of vibration/misfire while stopped - there could be a few things but what i am wondering is if you get this at a certain rpm like you said or if it's more related to the vacuum in the intake (and if you know where i'm aiming is the map sensor) - that one you can monitor with a multimeter but keep in mind that when you suddenly accelerate your vacuum goes towards 0 (so your voltage will go towards 5v) and then the more rpms you get the more vacuum so the voltage will decrease - what you want to look for is when you keep a certain position of the throttle and the rpms are steady at 2200 (or wherever you bad spot is) that your map sensor output is also steady and not making jumps up/down - and from there when slightly accelerating it will increase and reverse for closing the throttle.
could also be fuel related but in that case i'm thinking that you would get it at other rpms as well - map makes sense in this case but this is me guessing based on what you describe, can't be certain - i would test it though first - better if you have a vacuum pump and gauge to test it with your ignition on and the engine off (not started), hook up the pump to the map vacuum line and increase the vacuum slowly while you monitor the output - if your vac gauge is steady and your voltage output is not or you have a spot where the voltage is not what it should be then you found the problem (you can find the output table somewhere if you do a google search but most likely will be in kpa which is kilopascal and you'll have to convert it)
some auto parts stores rent out tools and they might have a vac pump there, could be worth a try - or you could also get a junkyard one and ask the guys there if you can try it out to see if that's your problem, most of them would let you do that with the map sensor since it's an easy check
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Well, I just went out and replaced the MAP sensor and still with no resolve. I tried to reproduce the effect while sitting and all I could hear/feel was a slight backfire in the muffler at random. Its so slight but when something like that travels up through the soft suspension and the lift, it gets amplified so I can feel it stumble a little bit. Its really just an annoyance rather than a real problem. I surely do not have any performance issues, cuz this little YJ can really get on it with no trouble at all. I gapped all the plugs at factory specs (that would be where I would have first started, then cap rotor and wires). And replaced TPS and MAPS sensors, I am at an even bigger loss. What gives? Whats worse is that I am obviously having a hard time trying to describe the problem so that I can get some help here. Come to think of it, I get that nasty hesitation when its cold as well, but is gone after it warms up. Or maybe the effect I am having is just much worse when cold. Either way its annoying.
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Could the problem be on the fuel side not the ignition side? :puzzled:
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I thought about that too, but if it was a fuel problem, would I be having this problem only in an RPM range and sporadic at that? I feel like its just something real simple and we are just beating around it. (happens to me all the time) Does anyone think it could be the fuel filter? It looks relatively new. The wear on the bolt heads on the straps look like it may have been replaced not too long ago.
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I thought about that too, but if it was a fuel problem, would I be having this problem only in an RPM range and sporadic at that? I feel like its just something real simple and we are just beating around it. (happens to me all the time) Does anyone think it could be the fuel filter? It looks relatively new. The wear on the bolt heads on the straps look like it may have been replaced not too long ago.
if it was the filter i would think that you'd see that problem when you floor it and not the other way around (meaning when you are in need of more fuel), but you say it goes away when you push the pedal - this would be the obvious logic but you never know. I can make other suggestions but i really don't want to be the cause of you going out and buying another sensor and end up at square zero again (i would return the MAP sensor if i were you, of course if the store would take it back).
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UUghh! This is annoying. I cant take it back. CarQuest policy that if you plug it in, you cant return it. But, I guess they would never know if I did or not. But I am a regular there. I might need to go to a different branch. Did anyone figure out what the original posters problem was? Maybe mine has something to do with his problem? I didnt check before typing this so sorry if that had already been resolved.
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UUghh! This is annoying. I cant take it back. CarQuest policy that if you plug it in, you cant return it. But, I guess they would never know if I did or not. But I am a regular there. I might need to go to a different branch. Did anyone figure out what the original posters problem was? Maybe mine has something to do with his problem? I didnt check before typing this so sorry if that had already been resolved.
well, that's why is best to test the sensor first or get a wreckyard one so you don't waste money. What year is your Jeep btw, i can't remember if you mentioned it or not.
so to recap - you have a 4.0 t/b, IAC (AIS) complete from the 2.5, tps from the 2.5, replaced the tps with a new one (for the 2.5 i assume) new dist cap, rotor, wires and spark plugs and the last addition is a new MAP sensor
the only improvement you had so far was that the rough spot is not as bad once you changed the ignition parts - correct?
when did it all start happening (when did you first notice the problem)? any specific event that you can correlate the problem with? was it right after changing the t/b with the 4.0L one?
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Well, the problem out here (Portland, OR) is that there are no Jeeps out here, just a bunch of XJs in the junk yards. So I didnt have any to test. That aside, it wasnt that big of a deal, it was only $30 at CarQuest. Anyway, I think it has been doing this since I bought it. THere were so many things this Jeep needed tinkering on and this is one of the last one, besides the bump steer correction/alignment issue. Its a 92 2.5 with 154k and I think you guys figured it may have a 3-4" lift. I have the shackle reversal done on the front and have nasty bumpsteer. No drop pit arm, no trac bar, no sway bar, no control arms. But I have the 4.0 TB and spacer, transfered the AIS and the housing as well as the TPS from the 2.5 with that conversion. cold air intake, flowmaster all with 4:11 gearing and 32/11.5/15 Wild Country XTS. Replaced the cap, rotor, plugs, wires, TPS and now I can ad the MAP sensor. The trouble I am having is sporadic and is hard to figure out. All I can say is that it feels like a misfire that causes the thing to buck and stumble just a little bit. When I sat in the garage and messed with it while sitting it made the misfire osunds that sounded like it was coming from the muffler but they were real minor.
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Could it be the O2 sensor? I might try unpluggin it to see what it does on the way to work tomorrow.
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I was just thinking about this problem and how to describe it as to possibly get better results here; It feels like there is moisture in the distributer cap. That feeling of misfire/hesitation when you get it wet. And sometimes it stumbles bad enough to drop the RPMS down about 10k. After replacing TPS, MAP and CPS (crank position sensor) as well as a fresh tune up, I am still at a loss for words. :confused: :brick:
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IAC valve motor on mine caused some similar issues.
Sensor inside the distributor causes these issues...
Failing alternator causes similar symptoms too.
Dave
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I had a similar issue and it turned out to be a bad O2 sensor...
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This only happens between 2200 and 2800 RPM. And its usually when I just barely let off the gas as to not speed up. I tried to reproduce the symptoms while stationary but all I could feel/hear were mild misfires. And my Jeep is so soft without trac bars or control arms, the symptoms seem to feel worse while driving. Its annoying. Has any of your problems produced any codes? I dont have any. What sensor is in the distributor? Thats where I am leaning since it feels like a distributor issue. I guess I can also try to run it with the O2 unplugged and see if that helps.
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What sensor is in the distributor? Thats where I am leaning since it feels like a distributor issue.
it's the camshaft position sensor and it is used to time the injectors (EDIT: to open them in sequence and be synced with the intake valve opening).
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I have been trying to find a video on Youtube on how to test the cam position sensor but I cant really find one. Anyone know how I can test it with an ohm meter? What about the AIS? I think I might have twisted the shaft a bit when I was cleaning it before I put it in my 4.0 tb. Do you think that would have anything to do with the problem?
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I have been trying to find a video on Youtube on how to test the cam position sensor but I cant really find one. Anyone know how I can test it with an ohm meter? What about the AIS? I think I might have twisted the shaft a bit when I was cleaning it before I put it in my 4.0 tb. Do you think that would have anything to do with the problem?
you need a needle type voltmeter,
you can find the testing procedure here: http://4bangerjp.com/forums/index.php/topic,7246.msg53622.html#msg53622
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WOW! That seems like those guys had a bigger problem than I have. Mine just has a little stutter at 2200 - 2800. Thats it. Not anything lower or higher in RPM. Those guys seem like they cant get it running or dies all the time. Mine runs great. Just that little problem area. I was thinking there was a way to test the cam pos sensor like the TPS, where you might be able to find that "dead" spot by turning it to increase or decrease resistance. Its obvioulsy not bad enough to pop any codes. Its under the radar I guess. Still havent tried to run it without the O2 sensor though.
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Since my problem is only at specific rpm positions, do you think there is there a way I could hook up a volt meter and have someone look at the meter when it hits those bad spots? I dont know what I could hook it up to if it is the alternator, o2 sensor or cam position sensor. It isnt having the RPM drop anymore, it just "sputters" a bit during those rpm positions. And almost every time, I can throttle past it if I am accelerating. It is really noticeable when I am at a steady pace and just barely let off the gas or hold it steady when it is around the trouble rpm areas.
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Since my problem is only at specific rpm positions, do you think there is there a way I could hook up a volt meter and have someone look at the meter when it hits those bad spots? I dont know what I could hook it up to if it is the alternator, o2 sensor or cam position sensor.
forget about the alternator, if it would be that bad you would see it on the dash voltmeter. for O2 you need an LED based AFR gauge, any voltmeter that is either digital or needle (analog) type is simply too slow to react (the O2 reading changes back and forth 10 times per second if not more) - also, if the info on your O2 is lost there will be a CEL as well, but not if the info from the O2 is wrong (which can be if let's say you have a ground loss with the O2 sensor ground coming from the PCM) - so you could check grounds on all your sensors to the pcm sensor ground pin and see if there is any loss there. Same for the cam sensor, but i can't see how that would be your problem without throwing a code (the PCM would detect missed signals from the cam sensor while the crank still provides info) and still would not be at a specific rpm.
You could monitor the MAP with a voltmeter (i know you replaced it though) and same with the TPS but that's probably the only ones that can be read with a regular multimeter - maybe the sensors are fine but you could get a bad connection somewhere, although in that case i can't see how it would be only at that specific RPM (or maybe that's where is the most obvious)
for cam and crank sensors you need either a logging device, an oscilloscope or a scan tool.
Is there a way you could record a video of the behavior (i mean while someone else is driving or the other way around)?
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On my 94 I had a weird RPM based miss, there was no sign on
the dash / voltmeter anything that there was a problem.
After about 2 weeks of this the alt finally just died and when I
put the new alternator on the miss was gone.
The alternator shop told me that if the brushes get tired or the spring holding the brush it
will start bouncing and arcing and it pisses the Chrysler computer off.
You could probably see it with a o-scope on the charging lead if I had one I'd try that... :)
Dave
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Just an update... The hesitation has gone down a bit. I feel it mostly around 2200 RPMs but occasionally I get a backfire that feels like an intake backfire if I rev it up to shift and when the RPMs drop right at the shift, I get a little backfire feeling. But obviously that is hit or miss since it has to be at a certain RPM to do this (the same RPM that this hesitation problem exists). I havent done anything to it yet. No time.
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BTW I've had 2 sensors that died within a day of install, 1 TPS and 1 IAT. :brick:
Dave
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Still havent figured out this issue. Now it seems like the dreaded bucking is coming back. I get a rpm drop between 2200 and 2800 RPM again. Its just a 5k drop but you can feel it. Like I am running out of gas (which I know the feeling cuz I did that last week too). And if I throttle through the bad spot and I just get lucky timing i get a backfire in what sounds like the intake manifold. My gut keeps pointing me toward the TPS but its new and never changed anything from the old one. But it DOES have to be in a certain throttle position and/or RPM range for it to happen. Mind boggling. :brick: :puzzled:
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Still havent figured out this issue. Now it seems like the dreaded bucking is coming back. I get a rpm drop between 2200 and 2800 RPM again. Its just a 5k drop but you can feel it. Like I am running out of gas (which I know the feeling cuz I did that last week too). And if I throttle through the bad spot and I just get lucky timing i get a backfire in what sounds like the intake manifold. My gut keeps pointing me toward the TPS but its new and never changed anything from the old one. But it DOES have to be in a certain throttle position and/or RPM range for it to happen. Mind boggling. :brick: :puzzled:
just for a test, try to unplug the o2 sensor and drive it like that to see if it changes anything - you'll get a CEL but will go away once you plug it back.
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I will try O2, there has to be a common fix to this problem....mine will spit and sputter at cruising speed, will feel like it drops power, floor it and it picks up and goes?????
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I will try O2, there has to be a common fix to this problem....mine will spit and sputter at cruising speed, will feel like it drops power, floor it and it picks up and goes?????
sounds like tps or map if it's not the o2, but that's just based on the couple of things you mentioned. there could be more than 1 cause for the same [sort of] effect so it's not sure that both of you have the same problem
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I need to see if my gm scan tool(auto xray) will let me scan it while driving....I'm not going to just buy parts to see what is wrong
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I need to see if my gm scan tool(auto xray) will let me scan it while driving....I'm not going to just buy parts to see what is wrong
you don't have to buy parts (i didn't suggest that) there are methods to test the sensors. It helps if you post the year of your Jeep, but if you're MPFI you can download the FSM and look for the testing procedures on sensors. Also if you have a CEL then the answer could be there. If you're OBD2 then yes, you can monitor your PCM while driving so that would work as far as diagnostic better.
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you don't have to buy parts (i didn't suggest that) there are methods to test the sensors. It helps if you post the year of your Jeep, but if you're MPFI you can download the FSM and look for the testing procedures on sensors. Also if you have a CEL then the answer could be there. If you're OBD2 then yes, you can monitor your PCM while driving so that would work as far as diagnostic better.
97 tj-4cyl
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please look at the ''air/coolent temp sensors'' and ''O2 sensor '' all of them will fight each other at times !i have used gm coolent temp sensor for some apps they work out better ..... sometime read the specs on the sensor ''temp vs. ohms'' find the most accurate range helps running etc
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Pulled the O2 and the bucking stopped. I really had to try to find the bad spot. But now, I have been driving it for a few days without the O2 sensor and the bucking is back. Does this still mean the sensor is bad or do i now need to look at the temp sensor?
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No more bucking and hesitation. Hopefully my gas mileage will get better too. It was obviously a faulty O2 sensor that was the main problem. Still feel a little stumbling around 2200 RPM though. No codes, so who knows. But much happier now.
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No more bucking and hesitation. Hopefully my gas mileage will get better too. It was obviously a faulty O2 sensor that was the main problem. Still feel a little stumbling around 2200 RPM though. No codes, so who knows. But much happier now.
Is this with a new O2 sensor?
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Make sure you reset the computer. I'll bet it learned some bad habits from the bad O2 sensor. :stick:
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Yes, its with the new sensor. How do I reset the computer? Pull the battery cable for 10 sec? Or can I use the OBD1 scanner to reset it?
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Yes, its with the new sensor. How do I reset the computer? Pull the battery cable for 10 sec? Or can I use the OBD1 scanner to reset it?
pull the ground wire off the battery and touch it to the positive - leave it off for 5 min.