Thread: 350 chevy belching black smoke

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I've got a problem with my chevy 350 that's driving me crazy!
When I go to start the engine, it cranks and starts right up but it runs like sh**. running on less then all eight and belching out black smoke. If I can keep it running for a couple of minutes it will start to run on all 8 and the exshust clears up and seems to run fine after that. After it sits long enuff (a couple of hours) the whole bad running - black smoke thing starts all over again. HELP!

Black smoke is gas. Adjust the choke.

Originally Posted by R Pope

Black smoke is gas. Adjust the choke.

Or check for carb leak down (ie: sticking float valve when shut off, etc.) Sounds like when it sets the fuel is running through. Or again it could just be the choke.

It's a Barry Grant road demon 650cfm with electric choke.
I was thinking choke also, so I disconnected the wires to the choke.
Seems to be no change in how it starts and still causes the same smoke and ruff running.

Disconnecting the wires on an electric choke will not stop it from closing. The 12v to an electric choke are used to heat a coil inside and to open it after a period of time. If you pull the wire off, it will keep it from opening. Sounds like it needs to be adjusted. Check your users instructions or contact Barry Grant for guidance if you are not sure how to do it.

Pat

Fuel getting by the float valve sounds like that might be the problem (?)
My setup in the car is kind of unusual because my fuel cell is mounted higher then the carb so if gas is geetting by the valve, I would never know because the fuel level in the carbs would not change thru the site glass on the bowls.

black smoke is fuel / no air...........white/ blue smoke is air / too much fuel . oh my god smoke is time for a new engine
when i lived in denver i ran the choke off the resistor at 9 v. helped delay the opening a little.

Sound like you have a Duramax diesel not a SBC. haha