The good news: I believe I have figured out the cause of the rough shifting I've been getting on cool mornings.
The bad news: It's a climate control leak! This is bad because I was
hoping I wouldn't have to take the dash apart to fix this problem.
This morning I got up a little early and tested the vac to my transmission. It registered at just under 6" hg at idle, down from 20.5" hg at idle when it's warm out (ambient temp.). Now before you freak out about the 20.5 number, realize I have an '85 CA car and the vacuum is a little different on it. In other words, the numbers on Diesel Giant's site and in other places may not be right for my car. I don't know what they
should be, though...so if you have any thoughts, please chime in.
Now it was a bit dewy this morning so I used the defrost, which I haven't touched in a while...and the shifting was great! I did some more experimenting and sure enough, smooth shifting with defrost on and hard shifting with it off. Previously I'd tried the climate control in various positions - different temps and settings - and it hadn't seemed to make a difference. Guess maybe I'd neglected defrost. I'd also given some vacuum to the blue/green line that I think goes to the climate control and it held the vacuum, but that was when it was warm out and the problem only surfaces when it's cool.
My purpose for posting this is I did some searching and it seems the vac setup for the climate control in the '85's is, once again, a bit different than the other cars. I noticed on one site I saw that they sold vac diaphragms for climate control, but they were only good through the '84 cars. So in other words, I'm not sure whether the info. I find will apply to my particular car.
If anyone has any ideas about why my shifting would be good with the defrost on but not off...please fill me in! And if you have some theory on how I could maybe fix it without removing the dash, well I'd love to prove you right.
Thanks in advance. Thanks also for reading this long post if you've gotten this far.