95 Camaro 3.4 when starting cold or hot it struggles to start and when it does it sputters then the rpms pick up to 1200 rpms then goes into idle. it runs rough at idle and the throttle response is sluggish. Ive replaced plugs, wires, three coil packs,and TPS. Also getting a funky exhaust smell every once in a while.It seems to be chugging like its missing a cylinder. Fuel pump recently replaced.

 

Sounds a bit like a vacuum leak, a vacuum leak will cause the engine to idle high and have poor performance. Check all the vacuum connections to include the PCV.

 

cleaning the throttle body may help the starting issues. Any idea what the iac counts are at? If they are high, mt 55 its time to clean it.