Troubleshooting a starting problem in 88' Accord

I have an 88' Accord that has a really funny problem that I can't seem to find the reason. When it is cold outside, you can start it up, drive about 3 or 4 minutes and then the car revs to about 3000 RPM and the only way you can keep it down is to keep it in gear. If you stop and turn off the car, you won't be able to start it for about 2 or 3 hours. We tried starting fluid in the carb, but that didn't work. We were getting a spark, and the battery was fine. Tried jumping it off, didn't work. I left it for about 5 or 6 hours and came back, and it started right up and didn't have any problem, I drove it home, which was about 30 miles and it didn't rev high or anything.

So, I thought that maybe I need to let it warm up before I start driving, so the next morning I started it up and let it run, about 5 or 10 minutes after starting the engine, it started reving really high, as before.

I took it to the mechanics, but as usual it didn't show the mechanic what it was doing. I actually took it in 4 seperate mornings. The mechanic told me that he couldn't really check the computer without it displaying the problem.

I bought a new (to me) car (90' Honda Accord), because the 88' was so unreliable, but I HATE IT... it is a automatic instead of a manual, it has more miles and they are all town miles (whereas the 88' is a good deal of Interstate miles), it is starting to fall apart (both CV's on both axles, brakes, needs tires), so I am trying to get the 88' back in running order so I can sell the 90'

If anyone could please pointing me in the right direction, please do!

Thanks,
Drew