Last summer my Trans Am out of the blue started to run rough during warm up. It will always fire right up and run smooth for about 30 seconds then starts to chug/lope at high idle warm up. The exhaust smells rich also. As it reaches normal temp it smooths out and runs great!

So far I replaced the o2, plugs, cap and rotor and timed it. I had the carb professional rebuilt to specs with a new choke that I confirmed to be working correctly. All of this with no change.

Are there any sensors that could cause cold warm up issues? The CTS looks to have been replaced at one time. I was thinking of trying that first.

Any help is appreciated. Thanks!

 

Sounds like the choke just warms up slow.

I don't know about this "had" "rebuilt" stuff. Totally foreign to me. Explain how that works.

This "professional", did they ACTUALLY TROUBLESHOOT anything; or did they just go through the motions and charge you? If it was my car, I'd be looking at the choke pulloff diaphragm, especially if the car ALSO bogs when the secondaries open.