carb problem?

[JoePorting]

You shouldn't be running any motor in the garage for any extended period of time. Pull it out in the driveway. Also, get a ventilation fan for the garage. To add to the good advice from above, I'd replace the sparkplug wires, distributor cap and rotor if they are old. Sounds like you might have a weak ignition system. NGK FR5's (summit part # NGK-7373) would also be a good idea as noted.

[Schurkey]

Still eye burning smoke in the garage.

Eye-burning, hard-to-breathe fumes from the tailpipe are high HC emissions, often the sign of misfire. If you have an exhaust gas analyzer, you might find high O2 readings also, which would confirm the misfire.

A cylinder-balance test might locate a dead cylinder at idle, but the misfire could be random.

Repeating because I haven't heard anything from you about misfire diagnosis.

[BrazilianZ28Camaro]

With 10.7 to 1 CR , I definitelly would go with NGK#6.

Before cchange ignition parts, check the spark by creating a GAP between the spark plug wire and any metal part of the engine. At 3/8" gap you must see a blueish spark.

If its orange or yellowish, then your ignition system needs attention. Check the ohm resistence of the spark plug wires for correct rating.

Check for dirty into the IABs and correct fuel pressure.

[runawy9]

I would like to thank everyone for their time and suggestions.
I haven't had time to work on this car as the owner has been on vacation.
I suspect the ignition or plugs are the problem and will update when i get a chance to work on it.
Thanks again

[runawy9]

Everything that has been mentioned has been tried.
The problem is still there.
Beginning to think it may be an ignition problem?
He has msd ignition but maybe the coil is bad?
Any thoughts? He is looking to swap carbs and see if that helps anything

[BigBlocksOnTop2]

Drill a hole in the dist. cap right next to a terminal. Use a timing light and ''shine'' in the hole looking at where the rotor tip coinsides with the terminal. They have to line up. I have had a misfiring problem.I removed the cap, bumped the motor to align the rotor tip with where the terminal would be.Reinstalled the cap and using a bright flash light I could see a hugh gap between the rotor tip and terminal. I made a new tip approx. .080'' longer in length. Engine a lot happier. The dist. is a ''Power Fire'', I believe a MSD copy, and I would not buy another.It does'nt matter who says they are good. They are a ready to run, but the module was removed to make this dist. mag pick up. Also the rotor tip to terminal phasing was off too....

[BigBlocksOnTop2]

Look at the porcelan insulators on spark plugs for cracks (I use a magnifying glass). Fire engine in the dark and look for sparking around spark plugs and wires. You may see something. Check electrical resistance of each plug wire.
I locked out the mech. advance and set timing at 36. Engine likes it and it fires right up, even hot. My engine specs. out close to yours ( 10.4 CR and 249 @ .050. In., 395 cu.in.).