New to XJ and getting my baptism by FIRE!

[Broken_ArrowXJ]

Hi everyone!
I just bought my xj on 4th of July, and have had a number of my questions answered by xjtalk..so I figured I'd join. The group is AWESOME! I'm still having some issues and dont know where to go next, so thought I would see what everyone else thinks. I am having the general running issues that seem to be fairly common. It is fishbiting (surging, stumbling) at higheay speed, occasionally rough idle and stalls but starts back up right away, and sometimes the idle is high...turn it off and restart and it is fine. Since I jist bought it, I did the smart thing and changed EVERY FLUID AND FILTER on the vehicle so at least I know what and when on those, but i have also in the last 4 weeks....
replaced ,radiator and all hoses and thermostat, IAC, CPS, TPS. Removed throttle body assy and cleaned 190k miles woth of carbon. new plugs,wires,cap&rotor.
It still doesnt go the way I would like...but it stops great since all the brake parts are new except master cylinder and vac booster. What should I look at next?? I'm obviously not new to wrenching, and enjoy it...but I figured my issues would be gone by now. I'm eager for some new perspective...PLEASE HELP! THANKS IN ADVANCE!!

[Broken_ArrowXJ]

Please...any suggestions would be a big help. I feel like Ive been too focused on one aspect (the throttle position sensor and IAC) and may have missed something. A different set of "eyes" may help me see something I have not thought about. since I didnt get the results I expected from what I have already done, Im a little suprised and dont want to just keep replacing stuff till it gets better!

[XJ Wheeler]

Well, as you may know there are many things that can cause this. Although I am no expert I would start by resetting the computer. Disconnect both battery terminals and touch them together for 30 seconds. Also I would check the fuel pressure and exhaust system. Might think about running a cleaner through the system too in case those injectors are cruddy. And just to reassure you there isn't many people on at this late our so you'll get more (and probably better :p) help in the morning.

And welcome to xjtalk! We're here to provide a fun place to help each other out. Bashing, flaming, and disrespect is something we strive to push to extinction so feel free to jump in and ask, post, comment, show off, or just chat. Congratulations on the Independence Day Jeep!!!

[4.3LXJ]

Welcome Mike, glad you found us. One thing I would suggest since you don't know its history is change out the O2 sensor. That may not cure your surging, but it will level the playing field for you and with reseting the PCM with the battery cable disconnect you will be able to go from there. Also check your hoses and vacuum reservoir for leaks

[bluedragon436]

I would say with all the items you've already tried swapping out, that I would do as these guys said and replace the O2 sensor and then reset the computer and see what that does for you.. Another thing that I was thinking could be an issue is a vacuum leak. I know with the Renix engines they have that plethora of lines that go all over the engine bay, as I replaced the one on my 90 XJ.. You can purchase a new vacuum harness through Amazon, I think mine cost like $30 or so shipped to me in Delaware, and it gave me every line needed with the exception of the MAP sensor line.. most of mine were missing and the few that were there looked like hell... so figured it didn't hurt to swap out.. Heck if I can't get my 90 running again when I get back stateside in roughly a week I might be able to sell you the vacuum harness and a brand new O2 sensor I bought for it if you're interested..

[Broken_ArrowXJ]

thanks for the replies guys! I have been checking vacuum lines and replacing and plugging like crazy. The previous owner fancied himself a mechanic, and some of his "modifications" have just left me wondering WHY!!! I paid $1300 so Im not bitchin'. I pulled the battery to reset things after the TPS went in this weekend, so if it doesnt unlearn its bad habbits I'm going to do the O2 sensor and go from there.

bluedragon...if your ride is dead I may be interested inall of it for parts. I need a new Np231 also, plus enough other odds and ends that for the right price, a donor car makes good sense. Im looking around. thanks again and will keep everyone updated on what happens.

[autotech98]

I dont know what year yours is but my 98 had a bad crank position sensor that would cause a rough idle every now and again.also had a worn drive gear on dist. Shaft.

[bluedragon436]

Hey Mike, you have a PM, whenever you get a chance...

[rabies]

acts 2:38 woooop

[Broken_ArrowXJ]

Update....

I was going toa buy the o2 sensor tonight,but the only place that had it in stock was Napa for $90. No way! Autozone had a Bosch for 47, so I ordered it. I wanted to do something tonight so I decided to pull the EGR and clean it out. it was full of carbon so it should be nice and happy now. Then I grabbed a piece of garden hose and started listening for leaks. I found one small one... and a huge one that made me say "how did I miss this???" In the main hose going to the ball under front bumper. Fixed them up and disconnected the battery to reset the computer, then drove it on the highway, in town, over the mountain...its running AWESOME. Im still getting the o2, & going to drive it to work tomorrow and see if it acts like a fool again...but for now, fingers crossed. Now to find a cheap xfer case. Thanks for the advice and i'll keep you posted!!
Mike (Not so broken anymore_Arrow)

[autotech98]

Glad to hear it mike! Vacume leaks can be a pain to find

[bluedragon436]

Got to love those pesky vacuum leaks...

[XJ Wheeler]

Good work! Either way it sounds like some much needed maintenance was taken care of. :thumbsup:

[BHK Okie]

Hey broken arrow is that as in broken arrow okla. ?


Sent from my iPhone using Tapatalk

[Broken_ArrowXJ]

Im glad it was ru nning crappy...in a sadistic and twisted sort of way. it forced me to fix some really evil stuff left over from the previous owner in stead of just putting miles on it. So far so good!!
I
BHK...the name is a reference to when an American military post is about to be overrun, it calls in air support from all available aircraft. Also...more obvious and direct, dont know if you can see it in the pics, but the antenna is an old "broken arrow". my buddy who was a marine pilot said that was its new name.

[Broken_ArrowXJ]

Well....spoke too soon. It just started not idling, stalled, and when i went back on the highway it started surging again. when i pulled in the driveway, it died. have to coach baseball tonight, but if I get a chance...I'll mess with it and report back. Tommorow if not later today. SMH.....

[bluedragon436]

Guessing there is still a vacuum leak or something... Seems like it's not happy at the higher speeds, and def not once coming off those higher speeds back down to the lower RPM's...

[Broken_ArrowXJ]

This is so bad I almost don't even want to type it...but the 'ROKEE left me dead on the highway this morning!! It was running rough intermittently last night going to ball practice, but never died...until this morning. It starts up, idles high for 5 seconds, then kicks down like normal but then falls on its face and dies. it was hard starting for a couple minutes, but fired up and seemed fine. I pulled back on the road and 20 seconds later started bucking, sputtered and died. I was able to do that about 15 times to go far enough to get off the road...and then a drag back home.

checking things, I have No vacuum leaks...fixed them the other night.
I didn't do the o2 sensor yet, but this seems like too big an issue to be caused by that. I figured to save my $$$ for a more crucial purchase.
To recap...new parts are:
Idle air controller
throttle position sensor
Crankshaft position sensor
Cap, Rotor, Plugs, wires.
Throttle body has been off and completely cleaned SHINY
All vacuum lines traced and leaks repaired.

This whole thing got worse after I reset the computer. I had used the meter to check the TPS calibration and it was way off...so after setting that properly, and fixing the vacuum leaks, I figured it was the right time to flash the computer. I has acted different ever since.

Anyone want to take a stab at this? I'm trying to get my hands on a Chrystler DRBII diagnostic tool to see if it is taking codes, but its probably unlikely unless I drop a bunch of cash. My brain is fried from over processing this...everything logical(to me) has been tried, even some illogical things. I'm open to discussion! lol. Thanks everyone for the help so far...

[rabies]

any codes? compression test? leak down test?
surprised 89 had CPS
you put in the right plugs? right gap? timing is set? try timing gun and twisting your dizzy. same as tps. loosen it and twist it until voltage reads right at idle.

[4.3LXJ]

Mike, here is a link to show you how to get your codes for free.

http://www.xjtalk.com/showthread.php?t=11570

[Broken_ArrowXJ]

ok...codes I'm not sure. It doesn't have a check engine light, and the diagnostic tool for a 89 is Chrysler DRb2. The renix is a PITA for diagnostic electronically. what I can gather online...its a specialty tool and it has to see issues "real time" because it wont store codes or flash them with the CEL the later model xjs will. so...Ive got some calls into my mechanics buddies to see if any have the old scan tool.

plugs are correct. old school coppers, gapped at 35.
compression was good...but didn't do a leak down test, but that would be a whole different set of issues. the motor is strong and pulls like a beast when it ran.

timing was set when I did cap and rotor...and the TPS was adjusted with a volt meter, took the readings and did the math...and set it dead on per specs right before I reset the computer.

I Just checked the MAP sensor with a meter and vacuum pump/gauge and it is good...

Got anything else???

[4.3LXJ]

Take a T shaped pin, available at medical supplies, insert in the back of the plug for the CPS and CKS and crank. Your ohm voltage meter should fluctuate up and down. It is done best with an oscilloscope, but you can check function in this way.

[Broken_ArrowXJ]

ok...so I went back over EVERYTHING I had already done as far as parts replaced, and rechecked all vacuum lines. I noticed the TPS was angled all the way down (connector side closest to the manifold) and NOT the way I had left it. Pulled out the meter and voltage was WAYY OFF!!! The mounting screws into the throttle body were not very tight, and the air tube from the filter can was putting pressure on the sensor and must have moved it. I recalibrated it and put a dot of red thread lock on each screw so it wouldn't loosen again.

I reset the computer AGAIN...took it out for a ride and running pretty good. I'm amazed how quirky this motor is. If this keeps up...I'll be looking for a 318 to drop in and rip this renix stuff out! I'll keep everyone posted and thanks for the suggestions.

[Broken_ArrowXJ]

well I drove it into work today 30 miles and no issues! there was no surging or fish biting at highway speed and idled smoothly at every stop. hopefully this fix lasts more than a day like the last time.

my question is does the emissions light on the 89 act like a check engine light? I pulled the dashboard panel that has the idiot lights looking for a CEL, and only thing close says "emiss maint". does anyone know what would make this light come on?

[bluedragon436]

Wow, yeah hope this works out this time round.. They are quirkily little motors... then again most vehicles with a TPS would do similar stuff if the sensor was that far off... Although the 318 or even better a 360 swap into the XJ would be awesome to see, hope this fix works for you.. at least till you decide it's time for more of that V8 powa anyways!!

[Broken_ArrowXJ]

It ran good enough to take kids camping in the rain with it! Whoo hoooo!