18rc carby issue

[Hash_ra23]

hi all
im a noob to mechanical side of things but i want to learn and am currently doing a carby rebuild.
I have run into something i dont understand. My choke wusnt working properly cos i had to hold the throttle open to keep it from dying in idle. When i pulled it off i noticed the choke wus always open:

So i figured i could just fix this in the rebuild. But my issue is that the choke housing doesnt have any hoses going to it or out of it. (previous owner):

^^^that hose coming off the choke housing isnt connected to anything.

^^^the outlet of the choke housing is just closed

Looking thru the diagrams i have for the carby, the choke housing looks different. Did the previous owner put another one on? anyone got any suggestions on making this choke work properly?
sorry if i sound noobish

[thechuckster]

the choke housing uses heat from the zorst, not coolant... that pipe should go down to a fitting on zorst manifold below the carbi.

suggestion? go to an auto-parts store and get the cheapest, generic, manual choke kit on sale and adapt it to your carbi. You might be able to adapt something that you find from a wrecking yard.

[MWP]

Find an 18R with a manual choke at a u-pull-it style wreckers.
I know the older RT104 Corona's (didnt have the bulge at the front of the bonnet) have this same carb with a manual choke.

Actually, its a pitty your not in Adelaide, i could have given you a full recon 18R carb with a tweaked (mechanical) second throat.

[Hash_ra23]

is this what should be connected to the choke? cos right now its connected to nothing.

If thats so can i just do that?
But what about the outlet?
What kind of choke do i have on atm?

Thanks for the help guys

[thechuckster]

yes - that should join the line on the carbi

...you live in brisbane - you'll need the choke for 2 months of the year - get a manual one and make your life a little simpler.

[MWP]

Isnt that an inlet manifold vac line?

[thechuckster]

nah - big red pipe is vacuum - the two smaller heat tubes go into the heat exchange area between the zprst & intake.

[allencr]

You've got a problem with the choke always being open, not closed, so
getting some hot air/heat to it won't do anything to help you right now.
I'd just adjust it, and fool with the hose later if it doesn't seem to 'come off of choke' soon enough when warming up.

[Hash_ra23]

You've got a problem with the choke always being open, not closed, so
getting some hot air/heat to it won't do anything to help you right now.
I'd just adjust it, and fool with the hose later if it doesn't seem to 'come off of choke' soon enough when warming up.

yeh im rebuilding the carb so the choke being open isnt the issue. If i run hot hair thru it from the connection previously, should there be an outlet in the choke housing? because as shown earlier theres only an inlet and the outlet seems to be blocked .

[bnicho]

Maybe fit a Weber DGV with manual choke?

My RT112 has a DOA choke (it's Auto like yours). I couldn't be stuffed figuring out what was wrong, so I decided to get rid of it.

You can always cut and mod the factory air filter base so it fits on the Weber and keeps the engine bay looking stock (if that bothers you).

Cheers,

[Gunna]

The only thing i realy kno about the 18rc carbies are that you can adjust the choke by undoing the three screws on the sorta round thing on the side and turning it to have the choke more open or closed. This probably dosnt help much but i thought id say it just in case u didint kno...

[Jax]

Take the black cove off and take a picture. These also had a style with a bi-metal strip/spring in them that connected to the ign. Not sure if there was also a style that hooked up to the engine coolant like on the old 2 lt cotinas.

[Hash_ra23]

heres some pics with the cover off:

I'm pretty sure its exhaust actuated. when the bimetallic strip opens up.

edit: i'm wrong the exhaust doesnt get into the choke itself. I think it just surrounds it and by conductivity the bimetallic strip heats up?
The strip doesnt actually open the choke tho. Anyone know how the choke lever is actually forced open? because its not the strip that forces it open.

[mike1980ra40]

Hi there, you'll probably find the choke breaker/opener diaphram is at fault not
neccesseraly the strip that heats up. I had similar issues when i was running an 18-rc.
choke breaker diaphram isn't part of any rebuild kit so replacing it is next to impossible.
grab a peice old spare vac tube, one end on choke breaker then suck on the other end,
while sucking put the tip of ya tongue over the end and see it it holds.

another alternative is to get one of those 50ml syringes from an auto store and use that
for suction and watch what the diaphram does.

[Hash_ra23]

Hi

What do you mean by "choke breaker/opener diaphram". Theres no diaphram as such as i can see. I'm assuming you mean what opens the choke? Well i really dont know what opens the choke, i assume its just vacuum that it opens by itself or something once the bimetallic coil has heated up.

I've pretty much given up on this, and am just gonna wire a dodgy manual choke up as previously suggested. I'm just hoping it wont fail the regoing process because of it.

Thanks for the help anyways guys