Ok, this is annoying and confusing to me and several other mechanic friends I've talked to about it. I've got a Holley 600 VS carb on my 350 and when it's cold out (freezing or below, sometimes even a bit above freezing) and I'm trying to start my car cold it floods out very easily. It will flood so badly that I have to pull every single spark plug and blow them all off with compressed air to clean them. A couple times it has flooded so badly that I've had to replace the entire set of spark plugs. Once the car fires up it runs fine, and during the summer I get decent mileage (14 or so in the city 18 or so on the highway) and my A/F guage doesn't read way rich, so I don't think the carb is adjusted all that poorly. I just don't understand why the car does this. I tried setting up the electric choke on it once and the car fired up immediately, started to rev up to high idle, then died. That was the first time I had to replace the plugs, because it was so flooded (from the choke) that the plugs were ruined. So now I run with the choke turned completely off, although I really wish I could get it set up to work properly. I really don't know where to go with this because the car runs really well once it's started and I never see any smoke from it but this cold starting thing is rediculous! Any help/advice at all would be MUCH appreciated! Thanks so much!

-Paul

 

All automatic chokes have a very important little piece called a vacuum break or a choke break. It's job is to open the choke slightly IMMEDIATELY after the engine starts to keep from flooding out the engine from a fully closed choke.

600 Holleys that have an automatic (electric) choke have a small vacuum diaphragm on the front/pass side of the carb that pops the choke open slightly as soon as there is engine vacuum (engine is running). That diaphragm must be hooked up correctly and be able to hold vacuum and retract fully. When properly adjusted it will pop the choke open about 1/8" or so as soon as the engine fires (i.e. vacuum is applied to it).

 

Good info, thanks for the description of how that's setup. Right now I have the choke completely turned off, although I'd really like to have it set up to work, but whenever I've set it up it's flooded the car out. I was told in another post that it's best to set the choke up when the temp is about 70 degrees, but it's winter in Maine and I don't have a 70 degree place to work on setting up the choke, so do you have any tips on how to set it up properly when the weather is cold? If I could get it working right that would be really nice, but I just don't know because like I said every time I've tried to set it up it's flooded the motor out really bad. Anyway, thanks again, and any advice would be appreciated!

-Paul