The four main adjustments possible with a non-independent rear end are toe, camber, caster, and thrust angle. Not all of them may be applicable to your Jeep, and the lower-price alignments may purposely avoid some of the more difficult adjustments, even if they are applicable. If it was mine, I would go with the old "Set the toe and let it go, do da, do da ..."
... I'll wait a week or two, and I'll put another one up. I would like to see what others have done.
Please don't wait that long, scanner. I doubt that anyone else could do better, but I also don't want to discourage anyone else from trying.
It' been almost a year. I haven't been posting any case studies because I've been submitting them to training organizations. This is one that I fixed a couple of weeks ago, and because the platform is so old, there isn't any interest in it.
This is a 1998 Dodge Pickup with a 3.9L V6. The complaint is that the engine dies intermittently, mostly after started cold in the morning. Once the engine was warmed up, the engine would die at random times, but would restart immediately.
It had been to another shop, and after a few hundred dollars spent on unsuccessful repairs, the customer decided to come to my shop from a recommendation by his uncle.
There is a catalytic converter code, and it was bad, and that's another story. The cat had no impact on the driveability of the vehicle.
Since there was a code for the ignition primary circuit, I decided to scope it out with my Vantage Pro, along with the crankshaft position sensor. The engine shuddered for a second, and I saved the file.
As you can see, it was running fine, it hiccuped, then continued running.
I think that if there were mechanical timing issues, the symptom would always be present, not a "glitch" like scanner is showing us. I'm going to assume that scanner gave us all we need to know in his scope captures ... if that's true, I think I have it, but I'll hold off with my guess until others have had a chance to play.
Battery voltage is supplied to the ignition coil positive terminal from the Automatic Shutdown (ASD) relay.
The Powertrain Control Module (PCM) opens and closes the ignition coil ground circuit for ignition coil operation.
Base ignition timing is not adjustable on any engine . By controlling the coil ground circuit, the PCM is able to set the base timing and adjust the ignition timing advance. This is done to meet changing engine operating conditions.
The ignition coil is not oil filled. The windings are embedded in an epoxy compound. This provides heat and vibration resistance that allows the ignition coil to be mounted on the engine
I say PCM is bad, anything else seems like it would cause a constant problem. And I once wasted a month on a 3.9 Dakota before seeing the PCM was bad. Had to use a fire extinguisher on it too. Wish I had let it burn.
The crank signal looks pretty clean (even during drop-out), and should (in my experience) be necessary and sufficient for a primary ignition ground pulse (which is lacking during drop-out). It is implied, but not 100% guaranteed from scanner's traces that there are good +12s at PCM pins 2 (F18) and 22 (A14). It is also implied, but not 100% guaranteed that there are good grounds at PCM pins 4 (K4) and 31/32 (Z12).
If these conditions are true, I can only conclude that the coil driver at PCM pin 7 (K19) is the source of the glitch. I would recommend a replacement PCM, after quickly verifying the integrity of the above-mentioned circuits.
Mikey, I wish you could come work in Walnut Creek with me. I don't think the boss could afford you though. Well he could pay you, but I don't think it would be enough for you live around here and support your Kia lifestyle.