Choke info needed

[77crewcab]

For the Q-jet I know there are electric, hot air, divorced chokes. Can someone explain how the hot air and divorced chokes work and attach. Also are the chokes interchangable. I haven't used a manual choke in years but it is so simple I kinda like it is there a way to hook up a manual choke to the q-jet. For instance remove whatever choke is on the carb and attach a manual choke cable?

 

[77crewcab]

ttt

 

[diesel4me]

Hand choke kit...

Most "hand choke kits" will have all the parts to convert an electric or hot air choke to manual operation--they give you a plastic black cap that fits where the OEM electric or hot air choke cover went,and a shaft with a tang on it that hits the choke lever inside the housing,and some brackets and clamps..a "divorced" choke might be the easiest to convert to manual operation,its fairly straightforward to see what you need to do it..the "HELP" rack at autozone has a good conversion to manual choke kit with all the required "dewhickies" to do it,along with the cable...

I prefer manual chokes--I get up to 3 miles more per gallon by not closing the choke at all in warm weather,and I open it a lot sooner than it would on its own in colder weather..but I nearly lost a motor when I let my friends sister borrow my truck--she closed the choke like I showed her,to get it started--but only opened it 1/4 of the way,and forgot about it the rest of the day! --drank a whole tank of gas,fouled my plugs,and it smoked some after that.. --must have washed the rings right out of it!

 

[dyeager535]

There are actually a couple of designs of hot air chokes (Cad and Olds IIRC) but both are probably pretty similar: (this is Olds for sure) they pull a slight bit of air through a tube that sits inside the intake up to the choke coil housing. Thus, the coil is warming up similar to the engine, not the carb.

The divorced style is pretty simple. Instead of a choke coil on the carb, the coil is mounted to the intake, with a rod going to the choke linkage on the carb.

No, you can't just take one choke off of a carb, and put a different one on. Some you can, some you can't, but the mounting points on the carb are not all the same. (personal experience speaking) You have to take them apart to tell and compare, at least thats the only way I know of. I believe most are likely to interchange, and a few oddballs out there.

The divorced setup worked great in my truck, and no complaints with the hot air on the Olds either.

 

[R72K5]

well this is a complicated one

the hnot air tube ones work like this:

one tube attaches to inbtakje and goes to choke hoiusing tghe other tube comes from top air horn of carb on back of air horn and runs to choke housing

the top end vacuum signal from the c arb sucks heat form the intake throguh the choke housing and spoing, thus opening it when engine warms up

electric ones will swap over to the hot air ones yes, these were all mostly 79 and up, both designs,

tjhhjery are 99% identrical

you need the electric choke style shaft lever inside the housing in order to convert from hotg air to electric and thats it
edasy swap, use the hot air housing as it is the same as the electric oens other than the hot air one has the opening in bottom front for the vacuum tube

just leave it there unconnected it will be fine, i do it all the time

chevy olds pontiac caddy all of them used both designs

[and then there is the third type of gm automatic chokes,

the hot air spring and rod mountged on intake
those carbs you cannot mount electric or hot vacuum housings onto

been there tried it

it wont work

the pedastal cast part of the carb housing for the hot air and vacuum choke housings comes out further from carb than the intake spring and rod ones do

yres its dark in here i cant hardly see my keyboard and i dont type cept with two fingers and i should turn on a light eh

good luck

 

[77crewcab]

Okay you lost me on that description. Do you have anypictures of the different types of chokes hooked up on the engine. I know about the electric, and have seen what I think is the hot air choke on a carb but not on the engine. What I am thinking of is round like the electric but has a port sticking out towards the front of the engine. I know the divorced mounts on the intake but dont know how. I have an edelbrock intake with a block off plate on the passenger side I was assuming was for egr but from your description sounds like it could be for the divorced or hot air choke. Pics of each would be helpful as I am lost now.

 

[dyeager535]

Cadillac hot air faces forward the ones I've seen. Non-threaded tube, looks like it's for a hose. I beleive some Chev's had this style.

Oldsmobiles hot air goes into the choke coil from the rear, and it threads on. This style I don't believe exists on any other engines, as the tube piece that goes into the intake is Olds specific.

You are right, all of them except the remote coil are round like electic, just minus the connector.

I'm sure someone can come up with pictures.

 

[77crewcab]

Does the hot air hook up to the vacuum switch in the t-stat housing or is that for something else. Does the divorced get the hot air from the exhaust crossover in the intake or is that just for egr?

 

[dyeager535]

Not sure where Cadillac etc. get hot air from, Olds ROUTES it through the exhaust crossover, but does not use the "air" from the crossover. Thats what the tubes are for. On those setups, air is pulled in from below the air cleaner on the rear of the carb.

I doubt the choke was hooked to a temp switch, once it's open it's open, (coil is what opens/closes choke with heat) so no reason to "switch" when it might possibly work.