I have posted twice before on this truck, and have received some well
thought out, knowledgeable responses, but none have fixed the problem.

I have changed:  Sparkplugs, Rotor, Distrib Cap, Sparkplug wires,
Coil.

I have convinced myself that the IAC valve, MAP sensor, Colant Temp
sensor, Air temp sensor PVC valve, Compression, are all okay(right or
wrong). I am aslo sure the Cat Conv(new) and exhaust system is Okay.

Only new clue is this.  I put another new set of plugs, properly
gapped, in and ran the vehicle 100 miles, and examined the plugs.  All
looked great except Cyl#4.  The plug had been firing but there was a
small carbon buildup on oneside of the ceramic around the tip.  No
sign of oil, or fuel(when the engine was cold I ran it 30 seconds to
see if I had a wet plug- -I did not).  From a previous post I said
that: When I unplugged the fuel injector on #4 it made little or no
difference.

Here is what I haven't tried.  Timing Chain, Cam Sensor(checked with
meter) . Crank Sensor.  Fuel injectors (I and the mechanic at Dodge
Dealership checked fuel preasure).

Any suggestion what I should check Next?????????? Oh, it has 135K 6
cyl. 3.9L 2wd.

Thanks; Rogerx