Died while driving

I6, Auto, 93 sport.
Driving to work last week when my jeep died on me. I didn't hear any odd sounds or anything out of the ordinary, just seemed like I ran out of gas. Called san diego's 511 and they brought me some gas, put it in, nothing happened. No start. had to have it towed home. Took the wifes car to work, got underway the next day, and when I came home to look at it, battery was dead (figure it is from repeated cranking trying to start it). Disconnected the battery (my first mistake) and took it to get it charged and tested. Everything is fine. Didn't hit me to think about checking for an engine code, until after I disconnected the battery. So now when I check for it, I just get the "battery disconnected last fifty cycles" code.

I had recently had a major problem a few months back where the O2 sensor wire had shorted out onto the exhaust manifold and caused a bunch of problems. In the process of that, brand new starter, new CPS, new fuel pump, new ignition coil.

I have a fuel pressure tester and I get 45 - 50 at the rail, and I also have spark going into the distributor cap, none coming out. This leads me to believe it's not the CPS. I replaced the cap and rotor, still had the same issue, so I took a friends advice and replaced my distributor (made sure TDC) still having the same issue. I think something might be wrong with the timing, but I'm not sure what could have caused it to just suddenly go bad while driving.

I've read up on stuff stuff about the possibility of it being the flex plate. I'm going to crawl underneath and check that. I'm also curious if I just keep cranking and trying to start the jeep 50 times, will that "battery disconnected" code go away and will it give me a real trouble code?

I'm getting rather annoyed here as not only is the jeep my toy, it's my daily driver, I can't be taking my wife's car from her as she is expecting in 3 weeks. I'm open to any ideas here, and I really hope that ramble made sense. In advance, Thanks . If there is a thread I missed during my search, my apologies for creating another one.

The only time I've had mine just die (without any warning) that I can remember was when a connector for the ASD relay came loose. I wiggled the connector and it ran for a couple of months and then did it again. I cut the connector out and soldered the wires together. Never did give me any code.

Just a wild guess, check for spark when the motor is cranking over. Double check your CPS wires.

Check the orange wire at the CPS or the sync (cam position) sensor for voltage. Back pin it and check with the connector connected.

And check the simple stuff, battery connection and ground. I clean my battery connections with sand paper and spray them with brake cleaner anytime they have been disconnected, then reconnect them. It is worth the extra ten minutes to be certain you aren't spending days troubleshooting and eventually find out it is something really simple.:doh:

I'd also check voltage at all the fuses, both sides to battery ground. I seem to remember a TSB about the nut coming loose on the PDC bus. Some of the fuses are constant voltage some only when the ignition is on.

Appreciate the response 8Mud.

I did think about the ASD, but correct me if I'm wrong, if the problem was the ASD, Wouldn't it cause a No fuel/no spark problem? I have good fuel pressure and I have spark going into my distributor, but I do not seem to get spark out of it correctly. Never on sparkplug 1, and intermittently on a few others. It's worth looking into though, and I'll check that tonight when I get home.

I checked for voltage when the jeep was in run, the orange wire for the CPS has 9.25V, and another wire had 5V (I don't remember which one it was, I got it written down at home) of course, I did this with the CPS disconnected. I'll try it again with it connected. I do think I will be buying another CPS though, since apparently they break so often, it wouldn't hurt to have one on standby.

I've checked all my grounds, and they test fine. Although it wont hurt to clean them thoroughly, so I'll do that this evening as well.

The nut for the PDC Bus, that should be the double bolt connector at the front of the PDC, close to the battery correct?

I'll double check all my fuses again, and check for voltages on them with the ignition in the on position.

I did check to see if I had any grounds where the shouldn't be any as well, and I wasn't able to find any.

I'm really hoping it's not my timing chain, since I really don't want to take the whole front clip apart. Although on the positive side, If I do that, it'll give me a good chance to fix a few minor fluid leaks..

Thanks for the info, I'll let you know what I find out.

Have you removed the cap to make sure the rotor is turning when your cranking the key? Had a car do this to me once.

scottmcneal said:

Have you removed the cap to make sure the rotor is turning when your cranking the key? Had a car do this to me once.

Click to expand...

I think maybe Scott has it nailed. The pin can break on the distributor shaft. When it breaks it can partially catch and/or let go completely.

One guy on the boards, a long time ago, had stripped teeth on the distributor drive gear. The shaft bushings can wear pretty radically, push the rotor shaft sideways and see how much lateral play you have. The shaft can also have a lot of up and down play, but in my experience this is less likely to cause much grief. Enough side play on the shaft and the rotor can contact the individual cylinder electrodes with catastrophic results.

I had the distributor cap off once, motor wouldn't restart. the middle electrode (carbon) fell out, no kidding. I didn't even notice until I tried to start and then went back and looked closely at everything I'd had my hands on (with a flashlight). I found the distributor center electrode on the ground, stuck it back in there and super glued it. It worked until I got new cap.

I wipe out the inside of the cap every time I have if off with a clean rag and a little break cleaner. The carbon dust from the middle electrode wearing can cause you grief. Crossfire from carbon dust or very bad spark plug cables, or broken spark plug electrodes (infinite resistance) can cause cross fire.

Weak spark can also cause you grief, the coil can melt down internally and partially short, causing a spark, but very weak spark. Kind of hard to describe, but I can tell by looking at the spark if it is good or not, if it is wide and yellow and splashes when you look at it, it is likely weak. It may also be low voltage going to the coil. Connectors corrode, relays get crispy. A good spark is mostly blue, narrow and sharp, you can hear it crack when it jumps.

I'm not real familiar with the 91-94 models, most of my experience is with the 87-90 models and the 95-96 1/2 models. Some of the stuff I've learned is universal for most XJ, some not applicable to certain models.

If you feel you have to pull the distributor out and look at the drive teeth or the shaft pin, do yourself a favor and find TDC 1. Line up the timing marks, by turning the harmonic balancer bolt, making sure your last turn is clockwise looking at the front of the motor (to take up the slack in the timing chain). You can back off a quarter of a harmonic balancer rotation and try again if you go past the "0" timing mark. Note, a lot easier to do with the spark plugs out. Mark the distributor location, I usually mark it on the case, for the rotor position. And install it like I removed it. The drive gears for the distributor shaft are helical, so you have to start your reinstall so the rotor turns as you reinstall the distributor shaft. The drive slot for the oil pump also has to align when your finished. I've never had a lot of grief with the whole process, like some people have.

A lot of this stuff you likely already know, but I recall this stuff like a check list in my mind and pretty much have to recite it the same way. I'm not the sharpest needle in the sewing kit.

General rule of thumb, if it is getting fuel and spark, in the vast majority of cases, something will happen, even if it isn't exactly correct. Just up and dieing is rare.

The IAC may stick shut, it will die and won't restart unless you open the throttle (give a little pedal) and may stall every time you release the pedal all the way. But this won't affect the spark any.

Sorry about writing a book, summarizing isn't one of my talents.

ScottMcneal, 8mud,

I did remove the cap and checked to insure the rotor was spinning. It is. The distributor and the cap and rotor are brand new. I ensured TDC before I removed and installed. I followed the instructions in the Haynes manuel. Was much easier than I expected. Car still doesnt start. Appreciate the idea though.

I didn't check to see if I was getting a solid blue spark or not, but my ignition coil is only 3 months old, Wont hurt to check when I get home though. Unfortunately due to my job, It wont be till later this month. Oh well.

While, I may have checked most the stuff you describe already, it doesnt hurt to see someone else suggest it, atleast I know im on the right track, and you never know, I might have missed something simple, so I will not complain about your check list and method of recalling.

I also checked voltages at all my fuses in the PDC, just to double check, all had 12 volts (with the exception of 1 or 2) and none of the fuses where blown.

By the time I got home yesterday and did everything around the house to prepare for my time away, I was not able to get to the parts store and pick up a new CPS, so i didn't get to try that. I did check the voltage of the orange wire on the CPS, with the jeep in run and the CPS plugged in. I got 9.25V. I dont see that extra volt being to much to fry the existing CPS.

While i was crawling around under the hood, I decided to remove my air intake hose off the throttle body and check to see if I could visually see anything wrong with the TB. As soon as I stuck my head in there, I got a strong smell of gasoline. Im assuming I flooded it, question is, did It flood while I was driving, or did it flood from all the times i tried to crank it and turn it over? I left the TB open for a little bit to try and let it dry out, but I ran out of daylight and it was getting late, so I had to secure everything and stop my troulbeshooting. I'll have to resume in a few weeks.

Short of pulling the whole front clip off, is there a way to check my timing chain, to see if that's the issue?

By all means though, I greatly appreciate the help, and if there is anything else you can think off, please, let me know, I'll check it.

Primary suspects for no-spark are the crankshaft position sensor and the ignition coil.

What brand coil did you install? There are a few threads about the MSD, ACCEL coils, failing prematurely.

Coil can be tested for primary and secondary resistances with a meter and a manual. Crank sensor can be tested, but testing is not always conclusive. Plenty of problems with aftermarket crank sensors; because of that I buy this part only from the Jeep dealer.

Link to crank sensor testing:

http://www.naxja.org/forum/showthread.php?t=1044073

To answer a few of your questions about the timing chain. First off, it would pretty low on my list of things to worry about, though most anything is possible.
If you can get TDC cylinder one and the rotor is pointing to (near) the number one pole on the distributor cap, the timing chain is likely OK. If compression is good, the timing chain is likely OK. If the cylinder number one rocker arms are all the way up, level and matched (equal height and you can wiggle them slightly) at TDC 1, the timing chain is likely OK.

I'd do an ohm test on the coil to distributor cap wire. And it is always possible the wire has a crack in the insulation and most of your spark is arcing to ground. You can usually see high voltage arch at night, in the dark or find it the hard way by feeling around the high voltage cables while somebody is cranking the engine over and you shock the chit out of yourself, usually in your fingers and out your crotch where it pressed against the fender.

I found this on the internut:

SECONDARY SPARK
Spark Test
1) Remove coil wire from distributor cap. Hold end of cable
about 1/4" from ground. Crank engine. Spark should be present and
constant. If spark is not present and constant, check coil and coil
wire resistance. Perform IGNITION PRIMARY test under IGNITION CHECKS.
2) If coil wire spark is present, ensure spark reaches spark
plugs. Check condition of rotor, cap, spark plug wires and spark
plugs. Repair or replace if necessary.
Spark Plug & Coil Wire Resistance
Resistance should be 250-1000 ohms per inch.
Ignition Coil Resistance Test
1) Remove primary and secondary leads from ignition coil.
Using ohmmeter, check primary resistance between positive and negative
terminals of coil. See IGNITION COIL RESISTANCE table.
2) Check secondary resistance between center tower and
negative terminal of coil. See IGNITION COIL RESISTANCE table. Replace
coil if readings are not within specification.
IGNITION COIL RESISTANCE TABLE- Ohms @ 75  F (24  C)

Application Ohms
Primary Diamond ........................... .97-1.18
Toyodenso ................................ .95-1.20
Secondary
Diamond ............................. 11,300-15,300
Toyodenso ........................... 11,300-13,300

IGNITION PRIMARY
NOTE: Perform SECONDARY SPARK under IGNITION CHECKS before
proceeding with test.
1) Ensure battery has a minimum of 12.5 volts (9.5 cranking
volts) available to operate cranking system. Ensure battery cable
connections are clean and tight.
2) Using an analog voltmeter, backprobe the following wires
at the distributor. Touch positive lead to Tan/Yellow wire (Gray/Black
wire Grand Cherokee). Touch negative lead to Black/Light Blue wire.
3) Set voltmeter to 15-volt DC scale. Crank engine. If
voltmeter needle does not fluctuate between 0-5 volts, check related
circuits. If necessary, replace camshaft position sensor. If camshaft
position sensor is okay, but engine does not start, see G - 2.5L & 4.
0L TESTS W/CODES article in the ENGINE PERFORMANCE Section and check
PCM.


If the usually suspects don't work out for you you may want to look at some less likely culprits.
I had trouble with the coil supply voltage on one 95 XJ. The dark green and orange wire going to the coil had way low voltage during cranking. It turned out to be a toasty connector. That dark green and orange wire is power for the coil, the alternator and the injectors. I imagine a lot of things could cause low voltage into the coil, the alternator shorting, injector shorting, low battery voltage (or amperage during start), a connector or even a bad splice.

The only time I have ever been able to flood an XJ was when the ignition system was all wet from a motor wash or driving through water or the IAC was stuck shut when trying to crank/start the motor.

If the IAC sticks shut and I flood it, I push full throttle and crank the motor over for 5-6 seconds, then apply 1/8 accelerator pedal and try a start. If the IAC is really stuck tight and you release the pedal and the IAC is stuck closed, the motor will stall from lack of idle air.

Lastly, new doesn't mean good, I've had many new parts that were junk and it seems to be getting worse rather than better. OEM parts are usually preferable, but expensive and some of them are junk also. Two out of the last three headlight switches, Jeep OEM, that I installed didn't last half a year and failed. I can recall at least 2-3 distributor caps that were faulty right out of the box over the years.

So I was finally able to work on it this weekend and this afternoon. I replaced the CPS, since I have a lifetime warranty, and figured it's a common point of failure right? might as well. Didn't start. Also replaced the IAC, since the old one was filthy and covered in oil due to some blowby I used to have. No change. Did that over the weekend, with the little time I had to work on it. Had more time this afternoon. Pulled out the 'new' ignition coil and tested it. It had 1.2Ohms across the leads, and then the lead for the spark plug wire had 7K to the other lead's. Little below the specks you guys gave me. Replaced with a new ignition coil, fired right up. And on the positive side, with the new IAC and the new distributor the idle and ride seem a whole hell of a lot smoother. Perhaps It's true, or perhaps I'm delusional. Anyways, I wanted to thank you guys for the advice and help, plus I wanted to let you know what it is. Since the ignition coil was still under warranty I was able to get a free replacement, so that wasn't to big a deal. Kind of annoyed that the previous new one had less than 500 miles on it though. oh well.

Easy fix; glad we could help and that you got it resolved. That's the beauty of this forum.

What brand of coil was it that failed?

I'm not sure what brand it was honestly. Got it from oreillys auto parts. Silver box. I'm just glad it had a warranty.