I have a 93 honda accord lx and when my car starts up after sitting for awhile I will put it in gear drive a few feet and put it in park again and when it idles it revs up and down. It seems like it does this till it warms up even in the summer. Also when its a really hot day or cold day. I will drive it on the highway and when I hold the peddle steady to not accelerate or slow down it revs up and down irradically. What can cause this? It gets really annoying on the highway. I thought it was transmission so I had the fluid changed recently. Please help.

 

I am having the same issue with my 92. Hopefully somebody else has had this problem and has suggestions on a solution.

 

I think i finally figured it out. it took me awhile but i found out that my EAC valve needed replaced and also had a vacumm hose that had a hole in it and it fixed my problem.