I have a 86 2wd SCLB truck with a 22r and column Shift auto with 127k i bought it not running and got it running easily with a igniter i had laying around and it started easily but when the choke went off and idled down it will not run unless idle is turned up high but when it drives it has plenty of power and does burnouts easily. At first i assumed i had a clogged idle jet but i had switched carbs so i assume that cant be it also i had thought about the idle air/fuel screw but couldn't find one. Ive tried changing the dissy and a carb i know works neither helped. I went on vacation and my dad said he would "fix it" i knew he wouldnt but he took it to a Shop and spent 100 bucks on a BS diagnostic They said it was the intake gasket and talked about something about gas in a vacuum line but I couldn't find any. So i replaced just the intake gasket. Still no luck, it got worse before it would idle fine with the choke on and would stay running but miss after it idled down but After changing the gasket it would not idle at all below like 2k i assume (has no tach) i have to hold the gas petal to keep it running. So i replaced it once and had no luck figured i did a bad job and did it again and re sealed everything on that side of the motor. Still no luck does the same ˟˟˟˟ and i have ran out of things to change. Any help would be great

 

If it's lean at idle, you should be able to slowly cover the carb with your hand and it will smooth out. If it's rich, it will stink like gas not burning. What do the plugs look like?

 

My truck is doing the same thing. I have done a full tune up and replace the fuel filter. Have been lost trying to fix it. At idle it sounds like my truck have a huge cam in it.

 

Just fixed my truck it had a vacuum hose that was loose. Did not come off just loose I replace with a new one. First hose on front right of carb.