I have a 1992 pickup that idles a little high at times and then so low that it shuts off when at a stoplight/stop sign. The truck will sometimes idle Dow and cut off when slowing down to turn on to another road. I've replaced some vacuum lines, I've used the carb cleaner. After the carb cleaner it seems to work better for a little while then it goes right back to a low idle. I really need help here so I'm open to all advice/suggestions as I'm looking to sell the truck but I don't want to sell it to anyone running like this until I can get it running right. Ill also say that while driving on the Hwy the truck runs perfect, only acts up when I'm at idle or at stoplight or stop sign. Please help.

 

Have you tried adjusting the idle screw?