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running ruff and dying

lost on a trail

NAXJA Forum User
Location
missouri
hello,first of all i have spent some time looking through here for similar post.i havent found anything that really helps completely.i have a 92 xj with 4.0,it started running ruff after i would shut engine off and restart it,it kind of acts like it is loading up fuel...i have to feather the throttle and it will finally clean up and run right.now all of a sudden its cutting out and stalling going down the hiway.....if i kick it into passing gear it takes right off and runs real strong,so im thinking its not fuel problem.......or am i wrong.any help would be appreciated as this is my only transportation.it is a 92 xj with 4.0 and auto tranny......have done a tune up with no help from that.
 
I'd try the key method and see what codes are stored. Could be a number of things. I'm not sure if a 92 will display the flashing MIL codes, but it's likely.
If no codes show up it can narrow it down some.
 
Check the Crank Position Sensor (they are notorious for such behavior) and also check the hose into the MAP Sensor (at both ends, including at the Throttle Body). If that is loose it will do exactly what you are describing.

Good luck!
 
Sounds like the O2 sensor is going bad. The ECU will ignor a totally defective O2 sensor, or a disconnected O2 sensor but when they get old and slow they do not respond fast enough and the ECU will try to run the engine with slow, or late O2 data. In other words the response is slow and the ECU makes bad A/F ratio data decisions making the engine run real rough. The ECU ignors the O2 sensor at WOT (Wide Open Throttle) so if it runs fine when you stomp on the gas, but rattles around at cruising I would disconnect the O2 sensor and see if the problem goes away. If it goes away you need a new O2 sensor. Don't just leave the O2 sensor disconnected or it will kill the gas mileage big time, and burn up your cat converter. It is save to disconnect for a test run.

If it is not the O2 sensor I would search here for Volt / Ohm meter test procedure for the TPS sensor next. They god bad, and cause some of your symptoms too. It is also possible to test the O2 sensor voltage output while the engine is running. That is also posted here in older threads.
 
hey before you go do all that time consuming stuff tighten down the intake manifold bolts thats what cause mine to run rough. its cause the computer has already calculated the amount of air then its thrown for a loop at the end or so said my mechanic once i gave up and took it to him. or it could be a bad gasket on the manifold.
 
sprry for taken so long to get back,medical probs.it was the damn ballast resistor.......took me a minute to figure that out.thanks for the help though
 
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