You may recall that I thought I needed a fuel pressure regulator from my problem thread. Well, I had ordered one just in case, and yesterday I put it on. It seems to have fixed a couple of problems.
Problem 1: If I stopped for a while when the engine was hot (i.e., to get gas), and then started the car again, the idle would "hunt" (go up and down).
Problem 2: If I tried to accelerate while going up hill, the transmission would downshift, and never go back into 4th gear after the climb, unless I put the car in neutral, shut the engine off, re-started it, and put the car back in gear. It was doing this occasionally on the drive home.
I read up online about problem 2, and the consensus was that the PCM will do this if it detects a lean mixture, and that a new fuel filter will usually fix it. My fuel filter is fairly new, but I was going to try changing it anyway. But after changing the FPR, the problem seems to have gone away, along with the hunting idle. I went on a bit of a test drive yesterday, and a longer one today. For today's test, I went up I-85 to exit 129, gassed up at Charlie's Race Track, and drove back home, being sure to accelerate up hills each way. Neither problem happened.
Now I think I can quit working on "White Lightning" for a while, and change the ball joints in my Ford Escape.