Help: XJ Wont start

[Bandit1]

Like the title says, the xj I sold wont start now. I have gone through the engine and checked everything I possibly could think of.

From what I was told, the XJ started the day they went to pick it up then got about a mile down the road and it just shut down and would not start again. From what I was told there was no noise, no nothing, it just shut off while driving.




The Jeep:


1996 Cherokee Country with the 4.0L I6.



What I have done so far:


Ignition coil- checked and is putting out 10-11V

Distributor and rotor- changed, brand new

Fuel Filter- changed and brand new

spark plugs- cleaned and gaped correctly

plug wires- checked and good (plug wires hooked to the coil and checked, all get the same voltage as the coil without wires)

fuses- checked and all good (bad ones replaced)



What I will be doing/checking:


every wire and connection I can find to see if there is a break in the circut or bad connection some where.



What I don't know/understand:

How does the timing chain/belt affect the rest of the systems? I have heard that the timing chain/belt will/can cause the problem, but I have no idea on how it affects the rest of the engine other than it runs the valves in sync with the pistons. But will a broken chain cause a no spark issue at the plugs?

What is the correct voltage that is suppose to be coming out of the ignition coil?



The problem:


After checking everything I could, replacing what I thought could be the problem, I found that the jeep has no spark. I did a continuity check on the new and old distributor cap and the center pin has no continuity even when the inside center pin is pressed all the way in. There is fuel pressure, and when you turn the key to the start position, it will crank over but not start.





What am I missing? What else is there to check? I would rather leave the timing chain/belt for last as I dont want to rip apart the engine unless I have to. I understand that the best way to know if the chain is broke to to open it up and look.

Thanks in advance to everyone that can help.

[egodfrey]

I dont think thats enough volts out of an ignition coil bud

[565matt]

Sounds like the crank sensor. It is on the bellhousing on the driver side. its right above the shift linkage and reads a tone ring that is mounted on the flywheel. I had this prob once and the jeep would just shut off when running. sometimes it would start back up again sometimes it wouldnt.

[Goonies.nsd]

Check for spark out of the coil and voltage in. But i would definatly start at the crank sensor. Very common and the symptom you described would have me start there. They can fowl out when hot and then work fine after they cool down. I highly doubt its chain related. Some vehicles spark is controled by a crank or cam sensor off the chain. But on the Jeeps its run by that crank sensor on the tranny bellhousing like he said. Good luck.

[Bandit1]

thanks guys, I will check the crank sensor on the next nice day i get up here. I will start by pulling it and cleaning it up before replacing it outright as it is an expensive part to buy.

[egodfrey]

didnt i suggest the crank sensor before on the phone?

[Tat2dfreak]

Some times if the crank goes bad it brings down the bus system and none of the gauges will work when you turn the key on, if you disconnect the sensor the bus will come back up and the gauges start working again.

[Bandit1]

didnt i suggest the crank sensor before on the phone?

Yea probably, but I remember you also saying about checking all the wiring and connections, dont remember you say about the crank sensor.


Some times if the crank goes bad it brings down the bus system and none of the gauges will work when you turn the key on, if you disconnect the sensor the bus will come back up and the gauges start working again.

I will add this to my diagnoses check list.

[tg426]

Do XJ's have ignition modules? I have had vehicles stop running just as described "there was no noise, no nothing, it just shut off while driving." and it was the ignition module.

[BermB1026]

I would pull the coil and give a good look at over for any hair line cracks. Similar thing happened to me last year. Or try cranking it at night and look for a light show. My money is on the coil.

[purple xj]

I would check that crank sensor there notorious for failing on a jeep

[silverzj]

pull off the distributor cap and have someone crank the car...if nothing is moving inside the cap its the timing belt and your not getting a spark

[Bandit1]

already done that the first time & its moving round in a circle.... LOL, it was just me so I had to set my vid cam, crank it then watch the vid LOL

[Bandit1]

ok, spent about 1.5 hours with the jeep, checking and cleaning connections, sensors and what ever else I could think of... end result, still no spark. I am going back up tomorrow morning with my electronics toolbox that I forgot at home today to test a few more things and see if i bypass the key and ignition switch if i can get it to start by "hot wiring" it.

Today I did:
took off and apart throttle body and cleaned all sensors
cleaned and checked crank position sensor- seems to be ok, no multi meter to check wires and circut with
visual check of ignition coil- no visable cracks


I am at a loss at the moment. I have no idea what else could be wrong and why its not starting.

[wb joe]

don you have to check the crank sensor with the meter it can look good and not be good, has to have a puls.also take a noid light and see if you are getting an injector signal. i think on the xj the crank sensor and the dizzy tells the injectors when to fire.i will try to get a wire scematic for you if you give me the truck info from all data.

[Goonies.nsd]

don you have to check the crank sensor with the meter it can look good and not be good, has to have a puls.also take a noid light and see if you are getting an injector signal. i think on the xj the crank sensor and the dizzy tells the injectors when to fire.i will try to get a wire scematic for you if you give me the truck info from all data.

Correct. No crank signal = no spark. I hate to say throw parts at it, but you may have to bite the bullit and do a crank sensor. They crack internally and can look fine. Cleaning them does nothing for them. Actually if there cracked cleaning them can fault them out.

[Bandit1]

don you have to check the crank sensor with the meter it can look good and not be good, has to have a puls.also take a noid light and see if you are getting an injector signal. i think on the xj the crank sensor and the dizzy tells the injectors when to fire.i will try to get a wire scematic for you if you give me the truck info from all data.

everything should be in the 1st post... what else do you need?

It is not my money being thrown at it, but the person who bought it... I know that sensor is an expensive one around 150 at AZ or AA, anyone know where to get a good one cheap?

Also, why would I get voltage out of the ignition coil but not at the spark plug? how does that work? Distributer cap is brand new

[Goonies.nsd]

OHH. You have spark out of the coil and going into the top of the cap?? But none coming from the 6 points on the cap cap to the 6 wires to the plugs? I was under impression you had no spark out of the coil? If so check the wires to the distributor for voltage. I believe it still had a 2 wire clip that ran to the distributor in 96. Im not sure what reading thru that wire off hand. If theres good voltage there, then it may be a bad distributor.

[Bandit1]

please see POST NUMBER 1...


The Jeep:


1996 Cherokee Country with the 4.0L I6.



What I have done so far:


Ignition coil- checked and is putting out 10-11V

Distributor and rotor- changed, brand new

Fuel Filter- changed and brand new

spark plugs- cleaned and gaped correctly

plug wires- checked and good (plug wires hooked to the coil and checked, all get the same voltage as the coil without wires)

fuses- checked and all good (bad ones replaced)

[Tat2dfreak]

So you have spark at the coil but not at the plugs, am i reading this correctly.

[Bandit1]

that is correct, I have spark up to the new distributor but not at the plugs

[stwilson74]

Your main coil output lead is only doing 10 to 11 volts? Thats a good place to start looking for problems, that should be around 30 times higher voltage, a coil is a step up transformer so if its just giving you battery voltage you have problems there.