350 Cold Start / Heat Stove / Vacume Flapper ?

[54blackhornet]

My 350 just won't start when it's cold, trying to reinstall the heat stove and original vacuume flapper device on the air cleaner to get some heat to the carb during warm up. Can someone explain the vacuumed hose routing from carb to air cleaner ? The 350 has its original Qjet carb which works great when it's warm but not so well when it's cold. Thanks guys in advance !

[trac209]

Originally Posted by 54blackhornet

My 350 just won't start when it's cold, trying to reinstall the heat stove and original vacuume flapper device on the air cleaner to get some heat to the carb during warm up. Can someone explain the vacuumed hose routing from carb to air cleaner ? The 350 has its original Qjet carb which works great when it's warm but not so well when it's cold. Thanks guys in advance !

Getting that working isn't going to make it start any easier. What it does is deliver warm air into carb until engine warms up. The vac line from the air cleaner goes to the vac line switch in the intake manifold and that gets vac from carb.

[Davidf]

+1, you need to adjust the choke properly. Many times, a homemade divorced choke rod is installed and the wrong length. Since you have the original Qjet, I am assuming you also have the choke spring mounted on the manifold. Ensure it is in good shape. Once you have the choke valve adjusted properly, set the fast idle screw as required to help keep it running on first start.

The proper rod can be found online. Example from Quadrajetparts.com:

Products
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1 x Rod, Divorced Choke - 1970-74 Chevy 350 Quadrajet (3089A) = $9.95

[54blackhornet]

Thanks for the information, only vacuumed port on intake goes to transmission TH350. Air cleaner vacume line went to carb originally I believe ? Can anyone take a photo of proper vacuumed line routing for 71 350 ?

[trac209]

Originally Posted by 54blackhornet

Thanks for the information, only vacuumed port on intake goes to transmission TH350. Air cleaner vacume line went to carb originally I believe ? Can anyone take a photo of proper vacuumed line routing for 71 350 ?

The vac switch I'm talking about is in front of carb and goes into the water jacket. When it reaches temp it switches off vac to the flap opening the door. You may not have one and will have to put one in to operate the flapper. But try's setting your choke as said above and see if that helps.