[Brock1030]

Just received back a great restoration of a 17059263 Quadrajet (pic attached) - thank you to John Herald and Ray Klemm - and now looking for a good source for a new or good used choke tube.

All I have seen available are those for the Olds 403 - nothing for the Pontiac 400 (in this case, a W72).

Kindly advise on best source. Thanks so much!

[nUcLeArEnVoY]

I feel for you. I find it frustrating that Inline Tube will not reproduce the choke tube set for the late 70's Pontiac motors. Especially now with how hot these cars have gotten over the past year, there is certainly a demand for them. There is a slight difference between the 77' and 78/79 W72 hot air choke tubes, so bear that in mind.

As for where to get one? I got lucky and grabbed a REAL nice set off Frank's Pontiac Parts this past fall for like $65 if I recall. The only issue with it, and something you need to be prepared for is that the tube that inserts into the base and leads to the carb may lose a tight press fit over time due to corrosion. You could try swaging it somehow. I went overkill on mine and brazed it to the base, but realistically, you can probably get away with high-temp Ultra Copper or Optimum Red RTV slathered around the tube and then inserting it into the base to form a seal. If you don't, then you'll be drawing in potentially dirty air into the engine since all the hot air choke essentially is, is a calibrated vac leak. It would also be a good idea to prime and paint it with high heat paint (VHT flameproof is what I used - I used their aluminum finish) to prevent corrosion, since that's what does these hot air chokes in over the years.

If you look on eBay, you'll overpay. Hopefully somebody here will have a good set for you. I'm with you in that the hot air choke will ALWAYS work better than an electric choke, if you have the parts. I used an e-choke on my W72 Qjet for a bit and it always took longer to open up. My hot air choke, I can blip the gas after 3-4 minutes and I'm at idle, and that's without an operating heat riser valve.

Good luck.

[Brock1030]

Do you have a pic of what the correct part looks like? Kindly advise.

Thanks so much.

[nUcLeArEnVoY]

Originally Posted by Brock1030

Do you have a pic of what the correct part looks like? Kindly advise.

Thanks so much.

Go to Frank's Pontiac Parts, and on their engine parts/engine-related page, toward the bottom of where you'll find all the hot air chokes listed by year. Most of them are already listed as SOLD, but you'll at least be able to see the differences.

They unfortunately go for a lot of money since it's a desirable part that is not repopped.

[Sirrotica]

I used to make them when I needed to replace them if the were missing, or rusted out.

I used a flaring tool clamp to reduce the size that slides into the manifold portion. I would use Nicopp line, as it is much easier to bend than steel line is. Before Nicopp line, many times I would use copper tubing. Flare the end that connects to the choke thermostat and you should be in business. It's a little tedious to do, but if you make a mistake you're only out a little time, and about 4 inches of tubing.

[Trevor78]

I was going to say the same. You can make something that looks similar, but more importantly, is functional. Then keep looking for original.

[Brock1030]

Thanks so much to each of you! Will keep looking.

[77 TRASHCAN]

Call Cliff, or convert to one of his electric chokes

[78w72]

i have a couple of these but as said they are hard to find & not a part i will give away too cheaply like i do many other small misc parts...

as for the electric chokes, i find they work much better than the hot air if adjusted right, the choke should not take 3-4 minutes to be at idle, especially on any late spring/summer temps, meaning not winter at 10f or something. i recall the manual states about 2 minutes is the time the choke should fall off the fast idle, in the summer mine will fall off fast idle after 1 minute or less... both hot air & electric.

2 of my pontiacs have electric chokes, 1 factory & one converted by cliff on my 467 stroker, both E chokes operate much smoother & more consistent than the stock hot air on my 78 T/A, both are newer chokes when rebuilt. i drive most my cars until it gets really cold or snows, have went to late nov or even early dec a few years, the hot air choke acts different in warm temps than cold, the E chokes stay very consistent. & a plus is you dont have to unhook the vac line from hot air tube to air cleaner every time you remove the shaker!

[Brock1030]

Sending you a PM. Thanks so much!

[nUcLeArEnVoY]

Originally Posted by 78w72

i have a couple of these but as said they are hard to find & not a part i will give away too cheaply like i do many other small misc parts...

as for the electric chokes, i find they work much better than the hot air if adjusted right, the choke should not take 3-4 minutes to be at idle, especially on any late spring/summer temps, meaning not winter at 10f or something. i recall the manual states about 2 minutes is the time the choke should fall off the fast idle, in the summer mine will fall off fast idle after 1 minute or less... both hot air & electric.

2 of my pontiacs have electric chokes, 1 factory & one converted by cliff on my 467 stroker, both E chokes operate much smoother & more consistent than the stock hot air on my 78 T/A, both are newer chokes when rebuilt. i drive most my cars until it gets really cold or snows, have went to late nov or even early dec a few years, the hot air choke acts different in warm temps than cold, the E chokes stay very consistent. & a plus is you dont have to unhook the vac line from hot air tube to air cleaner every time you remove the shaker!

In your defense, the reason my e-choke probably wasn't working so well was that I didn't have the little orifice in the choke housing through which the vacuum is sucked in covered up. Reason being is that hole also serves a second purpose as the bypass air hole for the later 70's carbs, and with my camshaft, I *NEED* that bypass air so that I don't open up the throttle plates too far at idle. I did have the threaded part to the choke housing that normally fastens to the hot air choke tube sealed, but obviously since it's an e-choke, you can't use a gasket for the choke coil cover, and so the bypass air hole was probably sucking in ambient air from around the choke housing cover - that ambient air getting sucked in may have been cool enough to delay proper heating of the e-choke coil, delaying its function? A bit of a reach, but it is possible. Also, that air was unfiltered, which further prompted me to go back to using a hot air choke.

I know that one option would have been to just drill an bypass air hole into the throttle plate/base of the carb like how they used to be done from the factory, but I'm trying to avoid invasively modifying my carb. I've gotten away with not having to change the idle circuit, thankfully. Wanna keep it that way.