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Post by Jay on Apr 27, 2005 10:47:10 GMT -3
ok this problem didn't really bother me before but i was out last night till 3:30 at work trying to get my jeep started. ill start from the beggening One time i was leavin college and when i got in the jeep to start it it wouldn't fire (just kept turning over) i called my dad and he said for the heck of it disconnected the negative turmonal and leave it for a bit. I tried it and it worked, it started up. It has happened once or twice but sometimes waiting or doing the battery thing fixed it. Then when i was at dicks tire barn it wouldn't start when i was going to leave (very embarrising  ) but the guy i was talking to there (a fellow jeeper) took a quick look and no spark was being sent to the distributer or coming out of the coil pack. But yet again takin the battery off and back on with some time fixed it. But last night it happened and wouldn't start. i tried the bat thing but it wouldn't work (killed my battery starting it and my spare battery) so when my friends got out of work they helped me and we tried checking the connections on the coil pack. they looked ok but after puttin em on again the jeep started. but after i accidently shut it off (forgot not too) and it wouldn't start again, messin with the connectioons again did nothing so i also tried the relays next to the coil (unlabled but i was in a wtf not state) and it started after. this morning it started fine but i was just wondering if anyone had a similar expericance and if u had a clue whats wrong. It only doesn't start, it has never stopped havin sparl once it's started so i'm stumped |
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Post by XfaCtoR on Apr 27, 2005 18:20:59 GMT -3
your have a sensor on the back or the block somewhere. its a TDC censor. there kind of know for going. i replaced it more then once on my dads mj. id check that tout. its a lil bit of a pain in the marbles to do..go get you self a jeep book like chiltons.
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Post by bluerocket on Apr 27, 2005 21:47:13 GMT -3
I would also check your crank position sensor, They are notorious for going on the XJ's. I know they will cause it to crank and crank but not fire, Can anyone comment on the CPS causing no spark? Or does that just make a mistimed spark.
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Post by mikeswrangler on Apr 27, 2005 22:51:31 GMT -3
I think both of you are talking about the same thing with the TDC and Crank Sensor. It is probably either, best bet your Crank Sensor which is right behind the back of the block it mounts on the tranny bellhousing with 2 bolts or your ignition coil.
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Post by sidriptide on Apr 27, 2005 23:50:03 GMT -3
you are both talking about the same thing.. there is no TDC sensor on the XJ 4.0L... the CPS is in the bellhousing on back of the engine and the pigtail plugs in to the harness right near the throttle body.. "XJ no start" is a very common problem on older (pre-91) models especially.. next time it happens try something else... find the CPS connection and disconnect it for a few mins... it should be a "flat" 3-wire plug that lead down behind the engine.. its the only thing on the manifold side of the engine that leads down there from area near the t-body... as stated it is a real PITA to change... best done from under the rig with a 2' extension and a flex/u-joint and a 10MM shallow socket IIRC... it may be a dealer-only item these days. expect to pay around $40 for it.. the tips are notorious for geting rust growing on them.. its not really cleanable/reusable... i can go on for quite a while about troubleshooting the XJ systems but try this link to NAXJA.org instaed.... i did a search on "wont start" read everything there and it will shed some light on how common this is... happy reading and hope you get it cleared up soon.. www.naxja.org/forum/search.php?searchid=467611 |
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Post by mikeswrangler on Apr 28, 2005 7:45:02 GMT -3
From what I remember they cost more than 30 bucks, I think it was something rediculous like 60. You can get them at autozone, lappens or any other parts store.
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Post by Jay on Apr 28, 2005 10:28:06 GMT -3
i spoke to the previosu owner at work last night and he said he'd bet it was the crank sensor, said he has seen same thing happen to 2 other jeeps and that was the problem. He said $30 sensor but is it a real pain in the a** to get to? (i think my dad has the chilton book) i haven't done much auto work but i did remove the tranny in my car, think i'd be able to fix this? keep in mind i have minimal tools
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Post by bluerocket on Apr 28, 2005 10:40:55 GMT -3
CPS all you need is an 11mm socket if my memory serves me. You will also need a 3/8th ratchet universal joint and a few extentions. Probebly 2 or 3. Getting to it is trickey, but thats the hardest part. Its on the upper Driverside part of the bellhousing, if you take a flashlight and look up there you'll see it no problem. Its held in by 2 bolts one on each side of the sensor.
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Post by jps4jeep on Apr 28, 2005 11:23:05 GMT -3
Just to interupt.. I also say CPS but you mentioned that you played with the pig tail on the Coil. I had a similar problem on my YJ, thought it was the coil altogether but...
The tach wire (purple/white) off the coil managed for some reason to pull itself off the connector enough not to make a good connection, then this was causeing a Lack of spark!
So I got a new weather pac harness and put that on, zip tied and taped the hell out of it Just in case!
Have not had a problem since and that was 3 years ago...
Just a thought for you to ponder.
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Post by Jay on Apr 28, 2005 11:32:10 GMT -3
hmm well it has been running ok today (wice yesterday) we checked the harnesses and they seemed fine, guess ill try the crank sensor since it was suggested here and by the previous owner (who is in school to be a mechanic and works on his own vehicles) $30 isn't a bad investment to try to fix it..if it doesn't work......  |
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Post by Jay on Apr 28, 2005 19:29:59 GMT -3
replaced the crank censor (goddam it is in an awful spot!) got a lil aggravated cuz i had to drive it to advance auto parts (cost me 31) but the trani was still hot when i started workin on it (had to get to work tonight). so far it hasn't done it so i beleive this was the problem, thanks again all!
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Post by bluerocket on Apr 28, 2005 20:06:55 GMT -3
You know if it was easy, then people wouldent take their cars to the stealership. Thats my feeling quite often as to why they chose torx bolts and Star bolts and all the other amazing design that goes into a car  On a Brighter note, Looks like i'm fabbing up a bumper for my XJ tonight hopefully. |
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) but the guy i was talking to there (a fellow jeeper) took a quick look and no spark was being sent to the distributer or coming out of the coil pack. But yet again takin the battery off and back on with some time fixed it. But last night it happened and wouldn't start. i tried the bat thing but it wouldn't work (killed my battery starting it and my spare battery) so when my friends got out of work they helped me and we tried checking the connections on the coil pack. they looked ok but after puttin em on again the jeep started. but after i accidently shut it off (forgot not too) and it wouldn't start again, messin with the connectioons again did nothing so i also tried the relays next to the coil (unlabled but i was in a wtf not state) and it started after. this morning it started fine but i was just wondering if anyone had a similar expericance and if u had a clue whats wrong. It only doesn't start, it has never stopped havin sparl once it's started so i'm stumped 
