Thanks for the tip. Actually, it doesn't sound that weird. I read that the electronics are sensitive to voltage fluctuations, so it certainly seems plausible that a faulty alternator could give me problems.

The fluid still seems fine, and doesn't smell. I took it for a spin around the neighborhood, and noticed the idle was also fluctuating. At idle it would drop to almost a stall, then the rpms would come up to just above normal idle, then repeat. If I rev it, the engine responds fine. It didn't have this symptom the first time around. Unfortunately, I've not really had any time to mess around with it.

Thanks again for the tip

 

I finally had a few hours to work on the car today. I decided to see if I could cure the somewhat irregular idle first. Pulled the intake hose, and sprayed intake cleaner on and through the butterfly vale. I believe the Idle control valve is right there, and the throttle position sensor. I sprayed liberally. I probably didn't do too much to clean the idle control valve, but I didn't feel like tackling the task of removing it and figured this couldn't hurt. I also adjusted the play in the throttle cables. Took it for a spin, idle seemed better, not perfect but better. Transmission wasn't acting too bad, but it did have some erratic shifts between 1st and 2nd.

I rechecked the battery voltage, 12.45, and checked the alternator output, 14.33. Both readings seemd where they should be.

Checked the resistance of the shift solenoids. Either side of the plug to solid ground, I got 18 OHMS. Both sides of the plug to each other, I got 35 OHMS. I think one side of the plug is a ground, so I'm not sure why the difference, however spec is 12-24 ohms, and I feel comfortable that at least from an electrical standpoint the solenoids check out. I read about guys getting readings of 800-1500 on solenoids that had toasted.

I removed the solenoids to take a look at the passages to make sure they were clear. They weren't. The screens were about 80-90% clogged. I removed them, cleaned them, and re-installed. took her for a test drive and the transmission shifted nice and smooth.

Perhaps the clogging is normal on a car with 180k miles that's only had it's fluid dumped once, about 80k miles ago, I don't know. Perhaps it's a sign the transmission is grinding up. The particles were super fine, but they were at least somewhat metallic (I checked with a magnet). In either case, I believe that this was the cause of my shifting problems. Maybe not the root of my problems, but the immediate cause. Figured I would share in case others wanted to check theirs. They were very easy to remove and clean.

Here's some pics of the screens with my garage light behind it so you can see just how clogged they were. Also a pic of the bottom of the solenoids to give a frame of reference.

 

Since the torque converter doesn't drain, you only drain about 1/3 or 1/2 of the fluid. You may want to do a couple more drain/fill/drive cycles to clean the fluid out more thoroughly.

 

Thanks for the tip, but I haven't actually drained the fluid yet. I just cleaned the screens on the solenoids. I ran out of time. It's parked for now, driving my truck for te time being. I'll be sure to dump run and repeat 3 times.