I have a 1987 Iroc Z 305 5 speed. The car has a very bad exhaust smell and a lumpy idle. I thought at first the exhaust smell was due to a leaky Y pipe,which is fixed now. Its almost like the car "loads up" at red lights. The longer I sit the rougher the idle and the stinkier the car.Then it will puff smoke when I take off.If I take it to WOT and then stop the car will puff smoke and smell.It never dies,Idle is around 1000 to 700,boucing between that rough. Vaccum is at 18lbs steady. New plugs,old ones indicated lean,they were white. I'm thinking maybe EGR valve,or injectors.What do you guys think?

 

Did you check the fuel pressure? Any recent mods?

 

Was Reading another thread, I always forget about the catalytic convertor, always take em off on my project cars. Rotten egg smell or ritch exhaust smell? Could be a plugged cat and blew out your y-pipe gasket.

 

I do have exhaust coming out of the tale pipe.I'm not sure about the cat being blocked.No recent mods. I got the car about 3 months ago,always starts,goes good,BUT smells.Only Mod I was put the new Y pipe on it so there are no exhaust leaks now,if that counts.

 

any ideas?

 

Yah what does it smell like, rotten eggs, too much fuel, does it smoke? You could do a search on how to measuring backpressure.