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I realy need help.

impetus-93xj

NAXJA Forum User
Location
Burnaby B.C
The story goes like this.... 93 xj 4.0 stock . Starts up no problem,runs for a few minutes then starts to stumble and quit. when I try to start it again..no go but if I wait an hour it will start again. So I was told that it could be the thermostat or the CTS. Well I changed them both and still the same problem. So tomorrow I'm going to change the fuel filter and I thought that when I'm at the auto store I'll get whatever else I may need so help me spend my money or help me burn the jeep I'm up to here with it.
:rattle:
 
It is not unheard of to have a coil react to temp issues. If your iggy coil is going, when it heats up it stops working, but the time allows it to cool down and work again.

What you really need to do is figure out what is not being supplied when it stops running. You need air fuel and spark. Before you just start throughing parts at the thing, figure out if you are lacking fuel or spark when it stops running. A new fuel filter won't do you any good if you are not getting spark. And a new coil won't do you any good if you are not getting fuel. :)
 
thanks for the info and I forgot to mention It being fuel injected and all I would normaly not touch the gas peddal when starting but I got frustrated and slamed the gas and it started breafly so whatever that means.
 
If you try it again and can get the jeep to react by slamming the gas pedal, i would have to go with the crankshaft positioin sensor route. Look on the fuel rail, there should be a valve that looks like it tire stem air valve. Push teh center of the valve down while having someone try starting it...if you shoot fuel up to the hood, then you are getting fuel but your injectors are not opening and that would be CPS. If you are not getting enough fueld pressure at the rail then you want to look at other fuel problems (like a filter) But this only applies if you get the jeep to start for a second when stomping onthe gas. Again youneed to comfirm the issue b4 you can fix it. Confirm fuel or spark first.
 
try the CPS. it's the sensor attached on top drivers-side of your tranny bellhousing. Mine just randomly died when it got warm, and wouldn't start for about 20 mins. I pulled it off, wiped it off, sprayed it with brakleen, wiped it again, stuck it back in, and it was fine! now It'll run all day with no issues!
 
thanks guy I'll try the fuel rail thing tomorrow and if thats not the prob then move on to filter. I'll hit you guys up for more info if that dosent work. cheers
 
also, another quick way to see if it is the CPS is that as soon as it dies, unplug the CPS, the plug is located on the driver side of the motor and it's right along the fuel rail, it is easy to spot b/c it is the only one that is runing to the bellhousing. Anyhow, unplug it and wait a second and plug it back in, if it fires back up easily...it is the CPS. And if it is indeed the CPS, be careful putting in the new one and do not drop a bolt into the bell housing. They are 11mm bolts if I recall correctly. It takes an ass load of extensions and I found it easier to unbolt the front drive shaft to get to it easier.
 
unplug the CPS, the plug is located on the driver side of the motor and it's right along the fuel rail, it is easy to spot b/c it is the only one that is runing to the bellhousing.

hmm... I went straight to the bellhousing..... ah, well...

I found it easier to unbolt the front drive shaft to get to it easier.

wish I wudda thought of that.....
 
I just dont know were to go from here . I've cheked the fuel rail after it died and it has pressure and ive tried un pluging the CPS after it died and pluged it back in again and no diference there, so what the heck ? oh ya and my soft 8s came today wish I could get exited
 
its throwing out a code now 34 which is cruse control but the cruse control never worked as long as ive had the rig
 
needsrepair said:
OK So after it died you got out and had the key in the run position and you pushed the valve and it shot fuel out?
it shot one burst of fuel out.
 
I'm just wondering if it had pressure at the moment it died. I usually connect a gauge, turn the key to on, you will hear the pump run, you should see good pressure. It should also hold that pressure when the pump cuts off. I'm not sure about our Jeeps, but my Chebby will hold pressure for a long time. Probably hours. If I watch the gauge while driving I want to see consistent pressure. If it died and I saw the pressure drop off I would be on to something. Another example: A guy had a van that would just cut off and then suddenly start back up. Well when it started back up, it would blow the muffler all to hell. Split it wide open. He could start it up and never would know when it would do it again. I hooked a tail light to the ignition coil and set it by his dashboard and told him to watch it when it quit again. He said it went out right when it quit. I turned the ignition on and sat and played with the key switch and after a while I could get it to find a dead spot. I then banged on the steer column several times and could get the light to go out. Replaced the ignition switch and it was ok. What I'm getting at is you want to pin point the problem through a process of elimination. Right now your engine quits. It needs compression, fuel and ignition to run. What are you loosing? Thats the question. Your not losing compression. Compression wont come and go. I would want to prove that the fuel pressure is there at ALL times. IF I watched a gauge inside your Jeep and it quit and the pressure stayed up, I would move on to the next thing.
 
it seems to run for about 10 mins or so then die. also if I run it for a minute and shut it down it wont start again. if I turn the key on the fuel pump will go on for a second and build pressure but if I press the button on the fuel rail it sprays one burst of fuel and thats it. I have two spare fuel pumps so I'm going to change this one and see.
 
If it will die out while your standing there without driving it, I would try this. Just as it tries to die out give it just a little shot of starting fluid. Don't blast it. Just go easy and don't over do it. Your trying to prove that its a fuel problem. If it picks back up and tries to run, you know it has a fuel problem. If it continues to die, it would seem that the injectors quit firing or you lost ignition
 
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