Stalling Problem on 95 Toyota 4Runner

I have a 1995 Toyota 2wd 4Runner, V6. Recently, it has developed a stalling problem when I first start it up. Sometimes it won't start at all. i have had the alternator replaced, the battery cables cleaned, and had 2 mechanics look at the car, but the problem persists. I have paid about $500 so far without success. Thanks very much! David Dean