Topic: 92 YJ 2.5 hiccuping under load

[Torch_Ind]

also don't account on new parts being still Known good especially after a year is gone by or umm more depending if you look at your receipts and go shit that was 4 years ago+.

being a tech I have heard that story a lot. wouldn't hurt to check the basics. spark like coil output/ cap & rotor condition/ fuel pressure during problem/ electrical aka wiring & fuses & relays, even battery volts say you let it sit for a bit battery gains enough voltage to start then volts go to high or to low causing things to shut down for the period of time.

Do you have oil leaks causing oil on the crank sensor?
sometimes the most obvious thing you already know about can be a cause of the problem.

[sirchesshire]

Ok.  Thanks for more great ideas!!!!!  Got her running again,    , once I figured out the problem with it not staying cranked was due to a fuel issue....the tank was empty.  (Go ahead and say it...I deserve it for not looking at my trip meter and realizing I'd driven that far.  That is what I get for driving too many cars.)

In answer to the last 2 posts... 1) I think I tracked it down to the TPS, especially since my PCM finally decided to show the codes (below) and that was one of them.  2) No oil leaks, sparks/wires/rotor good.

Back to the issues at hand.  I FINALLY got the codes to show up on my dash.  Codes were 24 (TPS), 21 (O2 Circuit), 51 (02 sensor).  Went out and bought the 02 sensor and going to drive for a while to see how it goes.

Replaced so far in the last month...battery, CPS, TPS, O2 sensor.  Will drive her for a few days to allow the PCM to learn the new components and then load her up with weight to see if the problem is fixed.

[sharpxmen]

Ok.  Thanks for more great ideas!!!!!  Got her running again,    , once I figured out the problem with it not staying cranked was due to a fuel issue....the tank was empty.  (Go ahead and say it...I deserve it for not looking at my trip meter and realizing I'd driven that far.  That is what I get for driving too many cars.)

In answer to the last 2 posts... 1) I think I tracked it down to the TPS, especially since my PCM finally decided to show the codes (below) and that was one of them.  2) No oil leaks, sparks/wires/rotor good.

Back to the issues at hand.  I FINALLY got the codes to show up on my dash.  Codes were 24 (TPS), 21 (O2 Circuit), 51 (02 sensor).  Went out and bought the 02 sensor and going to drive for a while to see how it goes.

Replaced so far in the last month...battery, CPS, TPS, O2 sensor.  Will drive her for a few days to allow the PCM to learn the new components and then load her up with weight to see if the problem is fixed.

 

but to be honest it happened to me once to call the tow truck for the same reason

my guess is it will run fine now since you replaced those 2 and had those codes - when my tps went south was running Jell-O mid throttle.


EDIT: for the record i didn't say jell-o, i didn't know that crappy spelled with an S is a restricted word :)

[carcollector]

Something I learned the hard way was to Always disconnect the battery to clear the computer for at least 30 seconds when you change the TPS or it won't make much difference - you might just want to do the same thing rather than racking up the miles and posing a threat to the cat

I think I am having problems with my CPS: runs like poop, cannot take a hard acceleration, dosen't want to start on the first try, has no power from takeoff when warm, minor backfires in the intake.... Does this sound familiar?

[johnbrakingground]

New to the forum, Have you tried replacing your Cat.  I had an 02 with similar issues replaced the cat and it solved it and got a lot better gas mileage. 

[sharpxmen]

New to the forum, Have you tried replacing your Cat.  I had an 02 with similar issues replaced the cat and it solved it and got a lot better gas mileage. 

actually that is a great suggestion, could be related - mine plugged so bad once i had to punch a hole in the cat as i could not drive it otherwise, so yeah, that can be a reason if it's semi-plugged and would explain why is more obvious under load.

[tommy69z]

where is the test port for fuel pressure? was going to put a gauge on mine, and did not see it??

[sharpxmen]

where is the test port for fuel pressure? was going to put a gauge on mine, and did not see it??

it's usually on the fuel rail in the middle, some TJs had it and some didn't. if you don't have one you'll need an adapter for the line.

[sirchesshire]

I've given it time and miles....to no avail.  The hiccup is still here.  Call my mechanic, he does all the work on all my vehicles, so he's willing to troubleshoot any time I call because he understands that I like to wrench on my Jeep.  Lets go back 2 years (I did check the receipts) and he is the same mechanic I took it to at that time....with the same problem.  He and I thought it was fixed at the time, then I changed jobs and didn't drive it for about a year because I was doing 150 miles a day and my Kia gets a lot better mileage.  Moved closer to home recently (same company) and now I can drive my Yj to and from when I get the urge (every time I walk out the door). 

After saying all that...I troubleshot with him over the past couple of weeks, replaced all the tps, cps, o2 sensors and still actin the same (to repeat my last paragraph only shorter).  Asked him about the cat, and he gave me the steps to check it myself...did so...no problems found without actually drilling a hole and putting a gauge on it.  His recommendation was for me to bring it in and he'd put one of his fancy new computers on it and drive it around for a few days for me.  $75-100.  That way I'm not just throwing money at my jeep (his words) instead of fixing the problem.  Sounds good to me at this point because I'm  !!! 

Will give updates when I take her in and get her back.

[sirchesshire]

Ok, so the mechanic couldn't find anything deffinate either.  He had to put 50 miles on her just to get something to show up.  The final decision was that one of my wires is broken internally and not giving adequate voltage.  So I guess I'll do ANOTHER plug/wire refit. 

He did say that the Bosch wires I was running have been causing a lot of problems with many vehicles over the last few years.  That could have been the problem in itself.  Guess I'll go to NAPA and get a "better" set of wires.

We'll know in a week or so, and I'll update again.   

[dwtaylorpdx]

I've always had good luck with the Echlin NAPA brand as well as Taylor.
Not flashy but really well made.

Dave

[sirchesshire]

The problem (I think) been solved.  Originally it WAS the cps.  Once that was fixed, there was a problem with the tps.  Then I went ahead and replaced a bad O2 sensor (wasn't actually causing a problem, but it was bad so why not right?).  FINALLY, the issue came down to a plug wire that was broken on the inside.  When I checked them, they all showed good...but the problem was occurring as I was driving down the road.  The mechanic drove about 50 miles and could only find the problem with a diagnostic computer attached that showed that one of the cylinders would occasionally not fire.  This was due to the plug wire literally being "barely wiggled" by the wind blowing through the engine compartment.  ($80 labor solution)

So I've replaced the wires, plugs, dizzy and button....and voila...no more hiccups.  (Saved money of course by changing them myself instead of letting the mech do it.  His bill for the putting on the $45 in parts?      $200 .....     ..... )

Now on to the projects...elec fan, 4.0 tb, wire my light switch into my ign swith...lots more tinkering to do now that I have resolution of the hiccuping. 

Thanks for the brainstorming guys.  I'll return the favor whenever possible.