How Quadrajet hot-air chokes work

There seems to be some mystery about how to get these old hot air chokes working again or working better. In this video, I use a complete mocked-up assembly to show you the parts to those systems and how they work.

These are commonly found on '76-80 Chevy V8's, and most years of Oldsmobile and Pontiac V8's.

[TruckThisGarage]

Man I’ve been looking for this video for a long time

[kenromaniuk]

WOW ! By far the very best video and explanation on this !
Thank YOU Tyler !!!!

[jackr]

Thank you WST! This is a great video and I appreciate your clear and impassioned ( I loved the "No! No! No!" ;) explanation. I've got a 1966 Tempest and I'm working on getting the choke correctly set up and behaving correctly. This video was really helpful. Please keep sharing the QJ love!

 Jack

[briankeery]

Tyler, thank you so much for taking the time to explain this in such depth. I had my original 1979 Corvette carburetor rebuilt a few years ago. The unit was engine tested with all new parts and a detailed description was sent back to me with the unit. In that description, I was given high and low idle settings, AF settings, and told that choke had been set. Since it was reinstalled, the car has ran flawlessly except for the choke coming off high idle. I've seen engine temps on my gauge hit 175F and the car still idle at 1700 rpms - even after hitting the gas lightly. It will come off if the car is revved to about 3500 rpms. Usually I have to put it in gear and once I've accelerated into second gear and gone about a block, she's always at a proper idle of 600 rpms when I'm sitting at the stop sign at the end of my block. I've verified that all linkages are free, and was concerned about messing with the choke coil, since I'd paid to have it set up. I had to ship the carb away for the rebuild, so sending it back wasn't really an option. Other than the initial cold start issue she runs great. This definitely gives me something to check thanks again, subscribed.

[torontochris]

So helpful thanks! I just found a severed tube in my manifold for a 73 Matador. My choke hasn't worked well for years! This video also applies to my 232 straight 6 with Carter YF.

[subarutruck]

Thanks much! I have a 57 Ford Fairlane 500 with 292 that you helped me fix. Your right, this is probably the only video that addresses this. I can’t thank you

[briansd]

Thanks for this video. Simple and effective system directly reacting in real time to what the engine is telling it.

[gravysnakes]

brilliant, many thanks. so helpful. I am researching why my car stalls when cold and this is the answer. (1978 Trans am)

[genokearney]

Thank you so much for this. It is still relevant today for restoration. In my case, a 1976 350 Camaro.

[Specialized]

Thank God I found your video. I just rebuilt the 350 on my 79 Gmc and had the carb rebuilt as well. I'm having problems with cold starts . The choke plate does not seem to be opening as I think it should. Seems to be sticking closed

[germanium]

Thank you for the video. It was so hard to find information about these choke tubes.

[hdfxe]

Thanks for posting. Always wondered how these worked.

[brianwelteroth]

Thanks for the simple yet thorough explanation.

[kimmijohnson]

loving that mopar in the back ground there bud lol

[RestorationObsession]

Perfect explanation! Thanks for posting this.

[billbaker]

Thanks ! was scratching my head on how this worked- the service manual was no help

[bonebone]

Thanks for the video. I wondered how this worked

[nathanstevens]

Thank you, this was hard info to find

[bebobism]

Mmm . . . I was wondering about this. Looks like I've got some problem solving to do, there's no heat crossover on my manifold. :) Thanks for the video.

[jnrayevr]

Great video thanks so much. Question, I'm workin g on this problem haven't gotten to the intake choke pipes yet to see what it looks like inside yet. But, behind the choke underneath someone tied a thin metal wire around one of the of the levers and it must of broke off but why do folks do that instead of replacing the part? Anyways I'm gonna keep looking and wanna thank you again for your videos. I'm working on a 1981 Chevy C10, 305, w400 trany. This truck ran pretty good till something made it lock out the choke plate on top. I may need to replace a couple of things but without these videos and some reading it can't get done sometimes. By now, JR.