High idle on each start

[Boog]

I've been working at a total tuneup on the '91 replacing most all electronics under hood since most everything on it was original 31 yr old with 82,500 miles. It's bone stock. The 350 is solid, no oil usage or leaks. When I got it it had some issues. It stalled all the time when stopped in gear and ran a bit rough so I started with a new dist, plugs, wires, CTS, IAC, 02 sensor, rebuilt throttle body with 2 new injectors. I used AC Delco parts where I could. Tested and retested for vacuum leaks. None. Cleaned all ground wires. I did a manual idle speed adjustment that cured the stalling issue. Driving down the street I could hear and feel the engine skipping but not enough to turn on the money light. Step on it hard and it would get up and go. Well lately when I start it up it idled well over 1000 rpm and would not come down while in park. Once I put it in gear it would slowly come down and wasn't too bad when stopped in gear with foot on the brake. Every time I started it it would idle high again regardless of warm or cold. After reading a thread where someone had it do just the opposite and he found a corrupted chip and mentioned corrosion in the ecm I thought I'd check mine. I removed the negative battery cable. I removed my ecm and opened it up and it looks brand new inside. All pins look fine so I just sprayed them good with electronics cleaner and put it back in.
On the next cold start it idled up more like it should, a good bit less than it did before. So I took it up town and drove around a while to let it relearn then headed out of town 30 miles or so. It runs much better with less noticeable skip. Pull up and stop and it idles smoother. Once home I shut it off and let it sit while I tended to something else for 30 minutes or so. When I restarted it again it idled up like the first start of the day. Once put in gear then back to park it comes down to a normal idle speed again. I have no tach so I cannot give rpms. I have no scan tool for OBD1. I'd like to have a cable to hook it up to my laptop and use Winaldl or TunerPro or similar to see just what it says.
I guess the battery disconnect reset the program so it started relearn clean may be responsible for the improved running. It's been a long time since I last had a TBI truck so I don't remember just how well they ran. It's certainly not as smooth as my LS trucks.
Anyone have a suggestion for a cable for a newish laptop with hdmi ports?