No idle

I have a 1988 c 3500 with 7.4 it will start but won't idle . I have to keep patting the gas to keep running . Any ideas?

'88 had the tb carb on right? the tb injectors drip during idle and spray when you give it gas. my guess is that the tb injectors are dirty and since it takes more force to push the gas thru the tb injectors at low pressure than high pressure.this is why it won't idle. they come off the carb and can be cleaned with carb cleaner.then put a bottle of injector cleaner in the tank. the tb injectors aren't to much to replace.but run a bottle of injector cleaner in the tank every once in a while to keep them clean.

'88 had the tb carb on right? the tb injectors drip during idle and spray when you give it gas. my guess is that the tb injectors are dirty and since it takes more force to push the gas thru the tb injectors at low pressure than high pressure.this is why it won't idle. they come off the carb and can be cleaned with carb cleaner.then put a bottle of injector cleaner in the tank. the tb injectors aren't to much to replace.but run a bottle of injector cleaner in the tank every once in a while to keep them clean.Thanx I tried that & it's getting better

it could be the DGR valve. i had the problem and replacing that fixed it