I don't know where these vacuum ports go
#1
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Car: 86 Firebird LG4
Engine: 350
Transmission: 700r4
Axle/Gears: 3.23 limited slip
I don't know where these vacuum ports go
My distributor has a port for vacuum so I assume one of these connects to that? Thanks for your help.
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Car: '86 Berlinetta
Engine: 305 stock
Transmission: 700r4
Axle/Gears: 2.73
Re: I don't know where these vacuum ports go
I may be wrong But i belive that it goes from the distirbutor strait into your carb should be on the passenger side twords the front and it is your vacuum advance and kinda important.
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
This is not a 3rd gen carburetor. It is a "hot air choke" system, and all 3rd gens were electric choke.
The 2nd pic is the choke pull-off, and needs manifold vacuum. The 3rd gen carbs had the pull-off on the front of the carb.
The 3rd pic is of the hot air heat exchanger that sticks into the exhaust cross-over passage. There should be a tube going from there to the choke thermostat housing shown in your first pic (needs to be metal with high-temp rubber attaching it to the thermostat housing nipple). It doesn't show in your pic, but there is another nipple on that heat exchanger that goes to the nipple on the top rear of the carb. How it works: There is a vacuum passage built into the choke housing. Air is drawn from that top rear nipple on the carb (filtered air), into and through the heat exchanger, into the thermostat housing, and then into the intake tract through the built-in vacuum passage. After the car is started cold, exhaust heats this little bit of air that is drawn into the choke thermostat, and this warmed-up air warms up the choke thermostat, opening it up.
The pull-off is a completely separate system, but it's function is to slightly open the choke butterfly after the engine is started cold, and after warmed up, to keep the secondary air valve from opening too soon and bogging the engine when going WOT.
The 2nd pic is the choke pull-off, and needs manifold vacuum. The 3rd gen carbs had the pull-off on the front of the carb.
The 3rd pic is of the hot air heat exchanger that sticks into the exhaust cross-over passage. There should be a tube going from there to the choke thermostat housing shown in your first pic (needs to be metal with high-temp rubber attaching it to the thermostat housing nipple). It doesn't show in your pic, but there is another nipple on that heat exchanger that goes to the nipple on the top rear of the carb. How it works: There is a vacuum passage built into the choke housing. Air is drawn from that top rear nipple on the carb (filtered air), into and through the heat exchanger, into the thermostat housing, and then into the intake tract through the built-in vacuum passage. After the car is started cold, exhaust heats this little bit of air that is drawn into the choke thermostat, and this warmed-up air warms up the choke thermostat, opening it up.
The pull-off is a completely separate system, but it's function is to slightly open the choke butterfly after the engine is started cold, and after warmed up, to keep the secondary air valve from opening too soon and bogging the engine when going WOT.
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Car: '86 Berlinetta
Engine: 305 stock
Transmission: 700r4
Axle/Gears: 2.73
Re: I don't know where these vacuum ports go
wow he made me look like a complete fool lol guess that is why he is a mod lol but hey i tried.
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