hey guys i have a 1990 xj that i just got last week did a starter ..valve cover gasket and a full tune up. it ran preety good but today it randomley shut off on me and will not start..its getting gas to the head and it has spark......anyone have same or similar problem could really use the help..0 i forgot to add that wen i turn the key it starts but soon as i let off the key it stalls out...when the truck was runing it would continue to run for about 10 seconds after i took the key out so my 3 gueses would be 1. ignition 2. cps or 3. tps

 

bump

 

Hmm tough one... I used to own a renix cherokee (like yours). Check your vac lines for sure.... Maybe bluexj is online, or send him a PM, he's the renix master.

 

well there was deffently a vacum leak proir and last night i brought it off roading for the first time because its only been on the road for about 6 days but i can see it being somthing stupid but i just cant figure it out

 

Sorry I'm not much help on this, but I'm scratching my head trying to remember... I had similar issues when I bought my 90. I did replace the fuel pump and coil...

 

ya my first thought was fuel pump..but i checked the little valve on the fuel rail and its getting fuel..brand new plugs wire cap and rotor aswell

 

Sounds like an ignition switch problem, check that first.
Then.
Fuel pressure.
If I am right, the 1990 needs the CPS (flywheel)to fire when cranking,
then needs
CPS and CKS (distributer) to keep running.
Use a battery powered timing light to check for spark.

 

You could probably test the ignition switch by jumping a wire from the 12v battery wire to the ignition wire and taping the 12v to the starter wire under the steering column if this is what you guys think.

http://www.the12volt.com/installbay/...tail/1150.html

 

by the way (as an ex car electronics installer) fuses are you friend for a weird test like this.... use them! Don't **** your **** up more then it is.

 

Does it just not wont to idle after turning on?
Maybe its the Idle Air Control Valve if so.

Check your Auto Shut Down relay I think your year has one. Swap it with another known good relay.
Also check fuel filter, even though you get some fuel the filter may limit the amount of fuel you are getting.

If none of that applys to you, ignore it, I am new and just trying out ideas.

I need to clarify, if your last part means the jeep ran for ten seconds after you removed the key from ignition or if you meant you let the key off start position.

 

I the ignition switch could be the culprit (let other people chime in to see what they think as I'm certainly no expert) and you would like to preform this test, the wires are thick gauge wires btw. You'll know when you find them opposed to other wires.

 

What's ur compression

 

after i removed the key it used to run for about 10 more seconds

 

the truck does not want to idle at all..i turn the key to start it it fires up then shuts off immediatley and i did a full tune up including a fuel filter last week

 

CPS, MAP Sensor, Clean IAC/TB. Check those.