Q-Jet Choke needed, what to do?

[andrewmckernon]

Hey everyone, I don't know if anyone realizes that I've got my car somewhat running now. I do need a choke though. I have a OEM Q-Jet and would like to put an electric choke on it, any ideas?

What about manual?

THanks

andrew

 

[78SilvAnniv]

I'm having trouble with my choke also. Kenny wants to put an electric one on the Qjet, also. I'll be interested to hear of any replies to this thread.

Anyone have a source for parts and directions for modifying to an electric choke for these C3s?
Heidi

 

[Vettehead Mikey]

Hey everyone, I don't know if anyone cares that I've got my car somewhat running now. I do need a choke though. I have a OEM Q-Jet and would like to put an electric choke on it, any ideas?

What about manual?

THanks

andrew

The bog-standard mechanical choke on these cars work just fine if adjusted properly. What's wrong with yours?

 

[cesully]

Mine no workie either... I have to baby-sit it to keep it running until she's at temperature. Any suggestions on how to adjust the choke without getting into a dissertation on the finer points of automatic choke fundamentals... in others words is there a fairly simple proceedure to get it working properly?

BTW- I have a 1978 L82 4-spd is that makes any difference...

thanks much for any input.

Regards,

Sully

 

[andrewmckernon]

I dont have a choke on my 69 350. It's just the carb. I live in texas and don't need it usuallly, but now that I have a huge intake manifold it's a necessicity.

andrew

 

[RodsnRides]

Q-jet choke

Hi folks -

I am not aware of a 12 volt electric choke conversion for the early model Quadrajet. However, this really is a great carburetor, albeit sometimes frustrating. The Quadrajet choke has several adjustments on it that make it function correctly. One of the most overlooked items is the thermostatic coil that is attached to the intake manifold and the rod between it and the carb. Typically, that is the thing that needs adjustment.

Sometimes the intake crossover gets plugged so the coil does not get warm enough to "relax" and the choke stays on-resulting in maintaining high idle after it's plenty warmed up. People then bend the rod so the choke will come off but then it won't function correctly when cold.

Since I am currently deployed overseas, I can't share the adjustment information just now. Now, I am assuming that most of you have mechanical skills and perform a lot of your own work. I suggest you do the following:

1. Purchase a NAPA/Echlin or Standard/Hygrade carburetor rebuild kit for your application-per the stamped number on the drivers side of the carb. This will give you the instructions that you need for doing the various choke settings. Plus, you'll have a kit for use later when you decide to refresh the carb.

2. Buy a new thermostatic coil, correct for your application.

3. Place the coil in the freezer to cool off.

4. Install coil on engine, connect rod.

5. Open throttle blades and see if choke flap closes. Check adustment per the instructions. You will need a drill bit set of various sizes to check everything correctly. You'll also need a hand vacuum pump (Mity-Vac) to check the choke pull-off diaphragm. They are also handy for checking the vacuum advance on the distributor. Plus, you can use it as an engine vacuum gauge for dialing in your tune-ups.

That's it. Heck, I can see a part-time job here rebuilding everyone's carburetor and setting them up. There are various services out there that can do it. I suggest a Google search on "Quadrajet carburetors". You'll find heaps of stuff. Good luck, everyone.

Rick

 

[MMM]

I totally agree with RodsnRides input. Having rebuilt over 300 Q-Jets, I find no reason for the stock choke system to be replaced unless your replacement intake manifold does not have a provision for the stock '68 "divorced" choke set-up. If that is the case you will need some sort of electrically operated choke, however I have never seen a kit to convert a divorced choke style Q-Jet to an integral choke type. The main body castings are differ between the two choke types. You would have to replace your carb with a later Q-Jet that was originally built with an integral choke.
For what it is worth, I have all of the Delco data on Rochester carbs from the 50's through '84. If you send me an e-mail with the model number of your carb I can tell you if it is original or not and if not original for what application it was intended. I can also supply the factory measurements for the choke pull off position. Let me know if I can help.
Mike

 

[69Shark]

Andrew,

I don't think you'll have to switch to an electric choke.

I had the same problem with my 69 and I purchased a new choke thermostat assembly and the linkage clip (all for about $20 from Corvette World ) - and that did the trick!

Hit me with an email and I can give you any details (part number, etc.).

Raphael

 

[81 Corvette]

no help here, but i wish i had a manual choke on my demon. My chock is wired open and unconnected. Takes about 5 minutes to warm up to the point where i don't need to touch teh gas.

 

[motorman]

Hey everyone, I don't know if anyone realizes that I've got my car somewhat running now. I do need a choke though. I have a OEM Q-Jet and would like to put an electric choke on it, any ideas?

What about manual?

THanks

andrew

go to www.carburetion.com/quadrajet.asp for a conversion kit. go to the bottom of the page

 

[RodsnRides]

Cool!

Wow, motorman, that site is awesome! Thank you for sharing. I've been having a hard time locating choke pull-offs.

Have you ever tried the divorced choke conversion? Does it work well? It has my interest...

Rick

 

[78SilvAnniv]

I mentioned this thread to Kenny this evening and he said our rod is bent. Does the carb kit come with a new rod?
He is frustrated and just wants to put in an electric choke. Me...I'll stick to the old ways as long as I can! Would this be something I could do? If I could fix it without him being involved, it would save the trouble of arguing about it.
Heidi

 

[RodsnRides]

Well...maybe

Heidi -

The choke rod is typically bent in an "S" shape. It's the amount of "S" that is an issue. The only analogy I can think of is the shape of the "S" is more subtle, such as a lightning bolt.

So the answer is, the rod is bent, you need to put the center kink in a vise and straighten it slightly. Again, the amount of choke flap closure needs to be measured. And your thermostatic coil is probably tired by now.

I did not realize the '78 Vette had a "divorced" choke. I thought (by then) they went to a "hot air" choke, little round tubes that go into the intake. I have worked on '75 and '76 Chevrolet cars that did. I just haven't worked on Corvettes much, but lots of Chevrolets.

Replacement divorced choke rods are availble. Edelbrock sells them for their 2101 Performer intake. Go to www.edelbrock.com and look up SBC intakes and accessories. I would try to paste a link or something, but I'm not as clever on the computer as lots of you.

I hope this is helpful. I remember when I first joined CAC you sent a friendly greeting. Thank you for that.

Rick

 

[69Shark]

Heidi,

I was also able to get the replacement choke rod from Corvette World, and it is indeed "s" shaped... the faulty one that was rigged on my carb from the previous owner was straightened out -- and was non-functional.

Raphael

 

[78SilvAnniv]

..."divorced" choke. I thought (by then) they went to a "hot air" choke, little round tubes that go into the intake.

I hope this is helpful. I remember when I first joined CAC you sent a friendly greeting. Thank you for that.

Sounds like something Kenny would need to do with me watching over his shoulder. As to the divorced choke, my vette is a 78, but the engine is a 1996 GM crate engine rebuilt this past year by us. I do remember when I took the manifold to the machine shop that it had a little plate that had a curved tube attached to what looked like vaccum ports. Is that a "hot air" choke?
Heidi

ps...I always try to be friendly and welcoming with the new members. I remember when I first joined CAC and Bud drew me out of my shell. Now they can't shut me up! :L

 

[motorman]

Sounds like something Kenny would need to do with me watching over his shoulder. As to the divorced choke, my vette is a 78, but the engine is a 1996 GM crate engine rebuilt this past year by us. I do remember when I took the manifold to the machine shop that it had a little plate that had a curved tube attached to what looked like vaccum ports. Is that a "hot air" choke?
Heidi

ps...I always try to be friendly and welcoming with the new members. I remember when I first joined CAC and Bud drew me out of my shell. Now they can't shut me up! :L

the "hot air chokes" have a stainless steel tube inside the manifold for a heat sorce. these tube get coated with carbon and do not allow enought heat to the choke on the carb so you must remove them from the intake and bead blast them clean for better heat transfer

 

[MMM]

Motorman,
Thanks for the information. I had never seen an electric choke conversion kit for a divorced choke Q-Jet. Now I know and it is a big help.
However, that not withstanding, I find almost all problems I have ever fixed
on Q-Jets to have been a result of the following, (in order of frequency).
1 - bad choke pull off diaphram
2 - weak thermostatic spring
3 - Bubba trying to fix something that he didn't understand in the first place
4 - Stuck heat riser or problems wth the heat tubes on integral chokes
5 - Carbon in the intake manifold heat cross over.
Factory installed choke systems work great, if the mechanic understands how the original factory system is supposed to work and assures all parts of the system are in working order and properly adjusted.
Now if the carb and intake are aftermarket then we have another story.
Mike

 

[Vettehead Mikey]

Motorman,
Factory installed choke systems work great, if the mechanic understands how the original factory system is supposed to work and assures all parts of the system are in working order and properly adjusted.

Truer words were never said, this also applies to 99% of the other components on the car. I doubt any of the 1000's of Bubbas will ever believe you though