'96 XJ stumbling when driving, but idles fine.

Ok so I'm having some trouble w/my '96 XJ. It's an auto, 206K miles, 4.0, 4x4 and this problem just started yesterday.

When I'm driving down the road all the sudden it started surging & bucking... then it'd drive normal, then it'd surge a bit, then normal, etc... It never died, but when I came to a stop the idle dropped to about 400rpm and then back up as though it was going to die. When the Jeep in in park it idles and revs just fine, but when I put her in drive/reverse I get the surging again.

I checked and couldn't find any broken vacuum lines or disconnected lines in the engine bay. I replaced the fuel filter and my fuel pressure is constant at ~ 51 psi.

The spark plugs and distributor cap have ~ 10-15K miles, but should be in good shape. I just changed the oil last week and that's fine and she doesn't burn any oil (Mobil 1 5W-30).

I found out I don't have an EGR valve (that's strange) or if I do I can't find it. Not sure where my Idle Air Controller is, but she idles fine... just surges under load.

Is there anything electronically that could be shorting out or going bad? Could this be transmission related?

Any suggestions for me to check would be greatly appreciated.

Thanks all

you don't have an egr...only renix
iac should be in the throttle body

maybe tps going bad.

The stumble it only appears to be when I'm driving.

I just went out for another drive after changing the fuel filter and it seems to have cleared up quite a bit. I still noticed some surging/bucking a little bit, but not nearly as much. I still think something else is going on.

I did notice that when I emptied the gas out of the old filter it was very very dirty...

Any suggestions to check let me know.

I had a problem awhile back with it not wanting to run under acceleration , but mainly when it was warm . Tirned out to be my coil was bad and it got hot and REALLY was bad .

Not a problem since. Worth a try if ya got a spare laying around .

Pour in a bottle of B12 and run it. It will fix it. I had the same thing happen. Oh is your speedo working right. A bad speed sensor will do something like that too.

x2 on tps. Will idle just fine, but will stumble and buck while under accel. Also check the distributor shaft for play.

Back up from the depths... but as a follow-up...

I changed out the Pre-cat O2 Sensor and also had to replace the distributor... as when I went to check the cap and rotor again I noticed that the rotor was VERY wobbly and loose. Replaced it and the O2 and ran another bottle of FI Cleaner and she runs like a top now. BTW, got 233K miles on the XJ now.