I have a 1994 z28 i bought off an older guy about 4 months ago who used it as a summer cruiser it has 170k and is completly stock. Latley the car has been struggling to maintain idol and start. When it does start it will die and then take forever to start again but eventually will when i start driving boom it will die again. I have been told it could be the IAC or a carbon build up the reason why I think it is the IAC is because this does not happen everyday or all the time but yesterday when it was bogging down and i had my foot on the gas to keep it going it was blowing black and grey smoke.

Any help would be appreciated

 

Black smoke usually indicates an overly rich fuel/air mixture. In other words the engine is getting too much fuel or it is not being burned properly. usually if you unplug the IAC and try starting it it will run very poorly and die. i'd do all the basics, check fuel pressure, check the IAC.

 

When was the last tune up done you should def. try a tune up as well if your getting back smoke... Plus run a can of seafoam through the engine because if it does have excessive carbon build up this will help remove a lot of that.

 

Any new news?

 

ahendrickso0963 has not been back to the site since early in the morning on 5/15.

 

like the man said black smoke is to lean of a fuel/air mixture.. another thing that you can do is clean the mass flow air sensor "with a special spray u can get at auto zone' dont touch the metal" and make sure that the mass flow air sensor is plugged in correctly. camaros of this year will happen to get colant in the distibuter some how. idk how thats just what i have read. also running bad gas can sometimes do the same thing so if u have been running bad old gas try running some higher octane gas in it to balance out the octane levels and after you do that reset the ecu.. if you dont know how to do that email me and ill give you the details its not that hard.
hope this helps a little