94 s10 blazer hesitates after idiling

[razor1049]

Hello i have a 94 s10 blazer 4.3 liter v6 (w) that hesitates after i have been sitting in a line..like a bank teller drive thru or long stoplight, it then it has black smoke coming out of the exhaust. it starts fine and runs good while its warming up but then after i do notice that it does idle a little bit rough and i have noticed that it does smoke black while i acclerate. i have had a computer on it but shows no codes. any suggestions would greatly be appreciated. gas consumption has become worse.

[big dwag]

it sounds like you need a tune up. when to much carbon builds up on your pistons it can cause them to blow black smoke from your tailpipe. change your plugs,wires,fuelfilter,distributor cap.

[Bronco2]

Black smoke is excess fuel. Is this a Vortec engine? If it is ,see the Blazer forum and you will find a bunch of info. Carbon buildup on your pistons will not cause this problem. I am not sure if the W VIN code in 94 is Vortec,but I know it is in 95.