i have searched the threads and see no matching threads so here is my question. I have an 86 trans am 4bbl carb electric w/electric vacuum advance. i just pu a national carbs stock replacement on the car. it is bogging under all conditions. starts up perfect but once the engine hits about 1100 rpm it starts bogging in park reving or on road does not level out or stop. it seems to be sucking alot of fuel. white smoke also from exhaust. it has a vacuum of 20. there is no affect at all when adjusting the set screws on the front of the carb. can close them all the way nothing, but if i tunrn them almost all the way out it will fire back thru the carb. usually if i adjust a carb all the way in the car will die but not this one nothing. if its not a carb problem could it be a timing or timing advance issue. thought of replacing the ecm since a friend of mine crossed the jumper cables once by mistake (right before other carb had problems). the motor was strong before previous carb problems (overflowing the fuel dumping it on the intake). sry for the long post just wanted to give good info thx

 

timing... probably better check that first - nothing will work well if that is out. ask the chevy dealer to set it to 4 (or 6 if you want) degrees before top dead center.

 

thank u for the info ill get the timing checked this weekend and post results thanks again

 

well the timing is spot on according to the oem specs guess maybe a bad carb ill see about getting it warrantied out

 

Before you send the carb back was it adjusted? Some on the car adjustments need to be made even after the carb came back from a builder.

About the white smoke. What does your oil look like when you pull the dip stick? clean or is there some other fluid also in the oil?

 

the oil is clean and looks new even when i change it after 3k miles never smoked before the last carb went bad tried to have it adjusted there has been no luck as of yet pulling my hair out as we speak