WHY hello there! so there's kinda already a thread on here that's kinda like this but iv already tried just about every thing that was suggested. and it also just sorta ended, but yeah so this problem set on over night, i have a 96 4.0 auto, the engine shakes pretty bad and it sounds like its repetitively misfiring. Its also putting out white exhaust that smells really bad and leads me to think its running to lean.. i dont know what the smells about though, but ahhh iv already replaced the fuel filter, spark plugs and wires, distributor arm and cap and tested my tps... so if anyone has any ideas of what the problem could be or what else i could check or test next ....i would uhhh.. say thank you

oh and i dont know if this would be related or not but the day befor it s### out on me i cleaned out the choke and then let it run just for a couple of minutes, ran just fine. then the next day shook bad on start up and thats where the story begins. i need help soon, a shops letting use there tools an junk to put on my lift in just a couple of days!!

 

oh and my cel wasn't on at first but just turned on today

 

ahh a 96 doesn't have a choke. white smoke is normally coolant or oil. did you replace the O2 sensor?

 

1. Pull those codes! The fact that you have codes and symptoms is not likely a coincidence. How to do so is shown below, although using a code reader or scan tool is preferred as it will give you the full code, which is more helpful than the 2 digit code.

2. Test your fuel pressure. Must be done with a gauge. For a 96, you should have 49 psi, plus or minus 5 psi.

3. Test your "map" sensor. And be sure that the vacuum line leading to that sensor is pulling good vacuum. The map sensor is involved with determining the fuel/air ratio

4. Replace your upstream oxygen sensor if it's got between 100k and 150k on it. Look for an NTK as a replacement brand.

5. Test compression on all cylinders. Can't overlook some sort of internal problem. The compression spec for the 4.0 is 120-150 psi, with no more than a 30 psi variation between cylinders.

Good luck and keep us posted!
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OBDII models (1996 and “SOME” 1997 models)

Put the key into the ignition, push down the odometer reset button, then turn the key to RUN with your finger on the button - and then release the button. The odometer will go through 1111111 through 999999, then display the car's serial number. It will then show the 2 digit error codes. The 2 digit code you will get using this technique is helpful, but it is not as specific as the full PXXXX code, which is only available using a code reader or scan tool, so generally I recommend using the code reader or scan tool. But if you have a CEL and don’t have access to a code reader or a scan tool, try the odometer technique to point you in the right direction until you can gain access to a code reader.

 

ahh sh**, sorry for the ignorance... but no i have not, is there anyway i can test it? and i did just flush an replace the coolant like a month ago and the oils only like 3k old. is there anything else it could be that i could check? as i am very poor.
and i do greatly appreciate you helping a newb

 

See the bottom of my post for how you can at least get the two digit codes. It's a start.

Post the EXACT code(s) here for comment.

 

thank you so so much that is exactly the kind of thing i was looking for. you are my savior!
i will without a doubt keep you guys updated. now time to get to work
P.S. that odometer trick is the coolest thing i have ever heard of! i did not want to limp it to checkers just to get that code pulled. i do uderstand it doesnt do the best but still awesome!

 

unless you have a scan tool so you can monitor voltage and sweep, checking ohms I just don't trust.

 

P0123 tps? i had that replace this year (under warranty haha)... and i checked it just this week.. maybe i could have missed something . is there any reason this could be going bad on me repeatedly?

 

First question. Where did you buy your throttle position sensor? Not unusual to have flaky results with some aftermarket units. Because of that, I buy mine directly from Jeep.

Also keep in mind that the code can be caused by the sensor, the connector, or the wiring. I usually get a can of electrical contact cleaner and some dielectric grease. Thoroughly spray the connector, add a dab of dielectric grease to the connector and reconnect. Any debris inside of that connector is a resistance path that can lead to issues.

 

so i just had it ordered from checkers not quite sure where they got it but tonight the replacement tps came in, so i slapped some electrically conductive grease on the prongs an hooked it up.. and it still started up rough and it ran a little less rough but still not great. i let it run for maybe 5-10 minutes,still not great but getting alittle better. i put in some injector cleaner and eventually all returned to normal or at least somewhat of how i remembered it. thank you all so much for you help, i know sometimes i can be a little hard to work with. but thank you for reuniting me with my baby!

LIFT HERE I COME!