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VERY strange & intermittent no start

TK99XJ

NAXJA Forum User
Location
Los Angeles, CA
Here is the rundown…

1999 4.0, auto 4x4; The no start condition is VERY intermittent in that it will not happen for weeks and then out of nowhere it will not start. When it does happen, it will do so for a couple of days on and off and then it will “fix” itself for another few weeks before coming back.

She will crank over but not fire. I have so far checked all grounds, the fuses, the relays and the large “BUS” connectors under the dash to the best of my abilities and all are in excellent condition and clean. I have removed, cleaned and reinstalled the gauge pod as I was getting the intermittent gauge issue that is common on the late model Cherokee’s and that had no affect on the condition. I have run a scanner on the PCM and there are no codes showing/recorded. I have cleaned and re-installed the NSS and I am 100% certain that is not it. I am also of the thinking that the CPS is not the problem either and here’s why…

Last night the condition arose yet again and after about 10 to 15 tries I got pissed and did the unthinkable, I smacked the Jeep pretty hard on the steering wheel and called her a bad name. I tried her one more time after that and she started right up!

Now that right there means to me that something is loose either under the dash or on/in the steering column. I removed the surround on the steering column just behind the wheel and all looks ok, cleaned the terminals on the ignition switch and clock spring with no change after the condition arose for a second time. After another 20 tries with no luck, one more good smack and she started up yet again.!?!

The fuel pump comes on every time, rises to the correct pressure and cuts until fired and when she is running, she is smooth with no stutter thus… I am guessing that the fuel pressure is up to par as well. I know that the PCM shuts off the fuel system if it does not fire after 3 seconds, so based on fuel under pressure in the rail I can only assume that it is in fact getting fuel at the correct pressure as I do not have a fuel pressure gauge. I have checked for spark and this is where things get interesting… I have no spark when the condition arises. Since a no spark condition leads me back to the CPS I am starting to think that possibly that is the issue here but the name calling and banging of the steering wheel makes me think otherwise!?!

What am I missing here? Thoughts/suggestions are GREATLY appreciated!
 
Latest... happened again at lunch and now the keyed tumbler/ignition is sticking/jamming and it is making it difficult to turn the ignition at all from the lock position.

The steering wheel does not lock, it never did.

This sucks!
 
Based on a few years experience with XJ's, my first bet would be the CPS. My guess that the bang on the steering wheel was an anomaly.

Now if banging on the wheel actually makes a difference, my bet would be on the computer connections. Unplug and replug the two connectors on the ECU under the dash, and yes you have to stand on your head to get to it.
 
Here's the latest...

The probelm is getting worse and now the keyed ignition switch it not turning freely. I squirted a VERY small amount of WD-40 in it to see if it would free it up a little and it did, but the no start condition still exists.

Upon searching the net for info on this condition, I found that a lot of late model XJ's have had similar problems that required new steering columns/keyed ignition switches to be installed. I have already replaced the steering column once (Jan 04) and I am not entirely sure why this would have any impact on the inability to get the XJ running. It will still crank freely, just no spark until I beat on the steering column.

Also (and this is going to sound stupid), are the late model XJ's equiped with transponder keyes? If the PCM is not getting a clean read on a transponder key, it could very well be the source of the no start!?!

I am at a loss...
 
i am having a similar problem with the 89 xj i have , i know that the computer systems are diffrent , and the the whole fuel injection system was revamped in like 92 or so . But it has a gm column / design, and i have never had a gm column have issues like that with the strarting, now the key not turning that is pretty standared when they get worn , simple fix you will need a steering wheel puller and a lock plate tool , should be able to rent from local parts store for cheap, and the new lock cylinder shouldn't be more than 15 dollars. it is just a screw that holds the lock in the column , do not drop the screw when removing , get a good magnetic screw driver to remove and reinstall the screw . it might get jambed down in the column and cause problems it is fairly easy and should take you no more than 45 minutes with the wheel puller and lockplate tool to do it . you then remove the turnsignal cam and the screw to hold the lock in place pull it out and reinstall in reverse . the starting issue i am still lost on .
 
I'm gonna take a wild guess and say change the ignition switch completely. It's a wild guess because I have not looked at a wiring diagram for your vehicle, BUT; if it has any type of by-pass in the start position of the switch itself, normal wear can keep the internal contacts from making. Just out of curiosity, is the column the ground to the chassis?
 
I'd check the ign switch too. Trouble turning the key is generally due to a problem with the lock cyl or the ign switch. Since you're having an apparent electrical problem starting, I'd suspect the switch.

The transponder keys work with the security system. I think they'd prevent it from turning over as well.
 
TK99XJ said:
Here's the latest...

The probelm is getting worse and now the keyed ignition switch it not turning freely. I squirted a VERY small amount of WD-40 in it to see if it would free it up a little and it did, but the no start condition still exists.

Upon searching the net for info on this condition, I found that a lot of late model XJ's have had similar problems that required new steering columns/keyed ignition switches to be installed. I have already replaced the steering column once (Jan 04) and I am not entirely sure why this would have any impact on the inability to get the XJ running. It will still crank freely, just no spark until I beat on the steering column.

Also (and this is going to sound stupid), are the late model XJ's equiped with transponder keyes? If the PCM is not getting a clean read on a transponder key, it could very well be the source of the no start!?!

I am at a loss...


Not sure if my problem is related but similar enough that I thougtt I would mention it. I also have a '99 4.0 at ~60,000 miles it started to stumble everyonce in awhile, this continued for abotu 1000 miles. IT than just flat out died as I was driving down the highway. Engine would turn over, but no spark. It was sent to the dealer and they replaced the wiring harness behind the dash, at least that is what they said. I's been running fine since then, 117,000 and still going.
 
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