stupid @#$#$@ transmission... help!

Here's the deal, as posted earlier last week. Went out and thrashed the crap out of my XJ last week in the snow.('89 auto) Coming home from Ft. Collins I noticed the thing wasn't shifting right, it didn't seem to want to go into OD. I dumped some "Lucas Trans Treatment" in it, and magically it started shifting again all nice, too nice. The oil was on the XXX part of the add on the stick, so I put in about a pint. I drove the thing probably about 100 miles or so and all seemed fine. Then I went to leave for work last night and it looks like the trans took a dump. Real bummer because I was planning on headin' to the Springs after work this morning. This is what it did: at first it would upshift to 3rd or so, but I had to really get on it. After I got out of town onto the open road, it went into OD or some variant of 3rd and would not downshift. After I slowed back down again no more 3rd. I only have 1st and 2nd. I have to tach it up to about 4k for it to shift between the two. It does not matter where the shifter is, it stays the same. When I let up, it seems to free wheel while coasting. Reverse works fine, no slipping. D to R engages relatively quickly and not harsh. Fluid level is fine, however it does appear to be abit cooked. Medium rare or so. I pulled the fuse marked "trans" on the fuse box, makes no difference. Is there another one elsewhere? I disconnected the battery for 5 minutes, the same. Any suggestions?

And the year of this stupid thing?

89 auto was mentioned
there's an inline fuse to the TCU, did you check that as well?

You may have something entirely different doing on than I had, but what you discribe does sound somewhat the same as what I had going on, only worse.
Like mentioned before check the fuse for the TCU and the TCU ground at the dipstick holder. Then check out your TPS (adjustment), clean the TPS connector well. If things don't improve you may have to check all the wiring between the TPS and the TCU. A quick test for the TPS through the TCU to dipstick ground circuit, can be made by back pinning the ground wire at the TPS connector (TPS side of the connector) with the connector connected and testing for *volts*, this is standing voltage that isn't making it to ground. There will be some, maybe 1 volt, likely less, the TCU has some resisitance built into the ground circuit.
Mine had variable (odd) shift points, odd downshift and coast, sometimes the shift to thrid was really late. The biggest improvement was cleaning the TPS connector (it smelled like WD40). Then adjusting the TPS to spec or just for a test to near 4.0 volts (3.8-4.0). Next biggest improvement was cleaning as many connectors as possible (especially the ground wires) between the TPS and TCU to include the TCU connectors (I found two loose pins). The next biggest improvement was cutting off the ground ring and soldering a new one on. My proble seemed to be a lot of little stuff that added up to a large problem.
I did a couple of Dexron changes at the beginning, just pulled the plug and changed what came out the drain. I did run the motor for a few seconds and put it into gear, to pump out a little extra fluid. Changed it twice over a period of a hundred miles or so. My philosophy with trannies is, change the Dexron often (like once ot twice year), I don't use any additives.
I also adjusted the TV cable in the beginning, just to double check and make sure it wasn't a factor.
My tranny seems to be shifting fine now (for the last four years or so), though the shift points do change slightly from time to time, not enough difference for me to worry much about. Even that stopped, when I got my charging system in order and put in a new battery. Most of the sensor (signals) are voltage sensitive, wild swings in (alternator/battery) voltage can't be a good thing.
I've never had a speed sensor (inside tranny) failure, there have been some posts about this.

Thanx guys. I didn't have a screw driver handy at work to remove the dash panel but did so when I got home.(27 miles in 2nd gear!) Anyhow, when I got home I disconnected the TCU and did the "shift test" as per the ATSG manual. It is working mechanically the way it should. Looks like I'll have to chase some wires or get it scanned. I atleast have hwy capable gears again! Since I'm pressed for time this morning I'm thinking about just running it to Co. Springs with the TCU unhooked, manually shifting. For the most part it's all freeway so no 2nd(I've had enough of that gear...) shouldn't be a big deal. I don't think it will hurt anything, what do you think? Thanx again!

Well then your problem is likely the TPS has a bad spot on the transmission side.

Running without the TCU, you won't have t/c lockup or 2nd which will make it run a bit hotter. If the TPS checks out fine, you should check the resistance on the solenoids (search for AW4 solenoids and you'll get a ton of info).

Thanx again guys. I swapped out the TCU while I was unplugging/plugging and that wasn't the problem. I think it may well be the TPS or a yanked or unplugged wire. I looked around underneath but saw nothing obvious. I did pack it FULL of snow so you never know. I'll let you guys know what I find. Thank #$%^& the trans doesn't hafta come out, all I need is another project! :roll: