# The tale of the happy litte '67 Tempest, with a not so happy chevy carburetor - oh and show me your linkage.



## Treozen (2 mo ago)

Hello forum friends (too presumptive for a newbie? ok...Forum Acquaintances)...

The GTO that isn't has been re-badged back to a happy little Tempest, and so I turned my attention to why the happy little Tempest is the hardest car to start....in the world.

It comes down to a few things - first, no choke. Second, the fuel bowl empties after shut down (which I feel like I remember is a common Q-jet issue) and overall the carb isn't really running all that well - not terrible, but not hardy optimal. I started with an electric choke conversion, only to find....nothing fit. Here's the lesson kids.....check your part numbers. Turns out my car has a Chevy Q-Jet from 1978, for a manual car. So other than "Q-Jet" that would be wrong. I've decided to get a rebuilt Q-Jet from Summit and now that I know the car is using a Chevy unit, I am unsure if I should switch back to a Pontiac design, or just get the Chevy version - same place, same price, same CFM - the only differences I can detect are in the throttle linkage and the choke. Here are my questions:


1) Would someone be willing to post a picture of their Q-Jet throttle linkage? I suspect my car has had the throttle cable replaced to match the Chevy carb - if so, I'll probably just use the Chevy version of the rebuilt unit - they also changed the fuel line routing too - so it would be the easier swap. BUT....if the linkage is similar, I'll put the Pontiac version on.

2) What CFM is recommended for a stock '69 400 GTO motor. Choices are 800CFM or 750 - I'm leaning (no pun intended) toward 750.

3) Other than the external linkages and choke - all of which may have been changed to fit the Chevy carb, is there any particular reason to use the Pontiac-type Rochester Q-Jet? As far as I am aware, there are no changes save for external connections (like fuel inlet) and throttle.

Thanks,
Allan.


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## BLK69JUDGE (Jun 10, 2010)

stock intake or aftermarket ??


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## geeteeohguy (Feb 2, 2008)

Here's my original '67 Q-jet on the original intake and engine. Fires right up with the stock chimney choke. No worries, 255,000 miles on the car.


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## goat671 (Apr 13, 2019)

For the Pontiac the fuel inlet faces the front for others it is to the side.


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## Treozen (2 mo ago)

BLK69JUDGE said:


> stock intake or aftermarket ??


Stock, though for a 1969 400 - 9794284 (could be 97942*3*4, but really looks like an 8 to me): I believe this is the intake from a 1969 GTO. 



geeteeohguy said:


> Here's my original '67 Q-jet on the original intake and engine. Fires right up with the stock chimney choke. No worries, 255,000 miles on the car.


Thanks geeteeohguy - appreciated. 



goat671 said:


> For the Pontiac the fuel inlet faces the front for others it is to the side.


Buick and Olds also I believe. Current carb is to the side - I ran the numbers and its '78 Chevy.


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## armyadarkness (Dec 7, 2020)

Treozen said:


> Hello forum friends (too presumptive for a newbie? ok...Forum Acquaintances)...
> 
> The GTO that isn't has been re-badged back to a happy little Tempest, and so I turned my attention to why the happy little Tempest is the hardest car to start....in the world.
> 
> ...


Read some of the Qjet reviews, BEFORE you buy one. It's widely considered that there are non good cores left to rebuild, and many of the people who buy them, never solve their issues. You could buy a new Edelbrock for the same money, and have a new carb with an electric choke.

I wouldve loved a new, rebuilt Qjet, but by the third "new" carb I returned, I gave up


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## Treozen (2 mo ago)

armyadarkness said:


> Read some of the Qjet reviews, BEFORE you buy one. It's widely considered that there are non good cores left to rebuild, and many of the people who buy them, never solve their issues. You could buy a new Edelbrock for the same money, and have a new carb with an electric choke.
> 
> I wouldve loved a new, rebuilt Qjet, but by the third "new" carb I returned, I gavve



Well, I ordered up the Q-Jet. The carb and company get generally good reviews and recommendations, multiple sources - which only means there's a chance it'll work right ;-) . For a while I had given up completely on Q-Jet carbs - in fact I think I have at least two in the garage attic, including an Edlebrock version. I had switched to newer Edlebrock carbs, but something changed some years ago and suddenly the Edlebrocks just wouldn't run properly - dead spots, hesitation, you name it. In fact I have a brand new 1411 electric choke on the shelf in the garage that never saw the road - I couldn't get to run properly (granted the car was modified and had a large cam) but I tried all the jets and adjustments - I eventually switched to a Holly - problem solved. That was the last Edlebrock carb I bought, and after fighting with several of them, I'm no longer a fan. I actually moved to a Sniper EFI system on a converted Jaguar MKII rather than use the Edlebrock....not that the Sniper worked either - lol. That car too got a holly (Summit version anyway) and again - ran like a champ out of the box. 

I'll let you all know how it goes. These stage II rebuilds are also engine-tested before shipping, which I like, and looking it over - the rebuild looks complete and well done. I hope to get it on tomorrow and I'll just need to find a source for the electric choke.


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## armyadarkness (Dec 7, 2020)

Everyone has their own personal carb preference. There's no wrong answer.

Both Edelbrocks and Qjets have legions of people who think they suck, yet all the experts disagree with both.

"Tuning" is a free skill, yet the vast majority of the world prefer to believe old wives tales and throw money at a car, vs diagnosis. Health care is no better.


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## geeteeohguy (Feb 2, 2008)

Cliff Ruggles has an excellent book on Q-jet repair and set-up. In my experience, on these cars, if you run a 4 bbl and are in the 200-650 HP range, nothing beats a Q jet set up properly on a stock cast manifold. Many tests bear this out. The advantage of the Q jet is that it's more finely calibrated to the car and engine and more efficient. Also, more power on the top end due to the design. A Holly or an Edelbrock (copy of an AFB, and the Carter is better) will bolt right on, but will not be as efficient or finely tuned.
These days, the Edelbrock is the standard 'cop out' for those who gave up on the original carb or simply cannot find one. Time marches on and these parts are 55 years old.


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## armyadarkness (Dec 7, 2020)

geeteeohguy said:


> Cliff Ruggles has an excellent book on Q-jet repair and set-up. In my experience, on these cars, if you run a 4 bbl and are in the 200-650 HP range, nothing beats a Q jet set up properly on a stock cast manifold. Many tests bear this out. The advantage of the Q jet is that it's more finely calibrated to the car and engine and more efficient. Also, more power on the top end due to the design. A Holly or an Edelbrock (copy of an AFB, and the Carter is better) will bolt right on, but will not be as efficient or finely tuned.
> These days, the Edelbrock is the standard 'cop out' for those who gave up on the original carb or simply cannot find one. Time marches on and these parts are 55 years old.


The big issue with the Qjet is cores. I tried too have Lars rebuild one for me, a few years back, and he refused all of my cores. He was adamant about it, too. Once the bases and tops are warped, and the throttle blade bushings are shot, and the internals have been drilled or epoxied, he wont touch them. I even tried to send him a new rebuilt from NAPA and Summit, but nope. 

I'd kill for a Qjet... but the new Edelbrock is a big improvement over the old one, and Ive been running them so long that I can tune and rebuild them effortlessly. And... both of my 67's had Carters from the factory.


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## Treozen (2 mo ago)

armyadarkness said:


> Everyone has their own personal carb preference. There's no wrong answer.
> 
> Both Edelbrocks and Qjets have legions of people who think they suck, yet all the experts disagree with both.


I used to be an "Edelbrock Carb Guy" ...I guess....in that everything that needed a carburetor got one. I started with Q-Jets and attempting to rebuild them, back when I first started, but as @geeteeohguy points out, it got harder and harder to find them. I moved to the Edelbrock square bore type at first out of necessity, but soon I had several of them running well and I got to like them - Everything from my '76 Camaro to my '57 Chevy had one. Then, I want to say about 8 - 10 years ago or so now, I had bad carb after bad carb from Edelbrock - I gave it another shot there about 6 years ago and as I said above, no amount of tuning and tinkering got the thing to run properly - the Holley by comparison darn near ran out of the box - although even it needed a few adjustments to jets and such given the application. I'm really in the camp of a good running carburetor, I don't have a design loyalty - though recently I have had more consistent luck with Holley or Holley-like designs (except their EFI Sniper system....)

As far as this Q-Jet - I got it installed today and so far, everything looks good. Fired up first touch of the key, and ran / sounded better than it ever had before. I also discovered a few likely vacuum leaks and fixed them, so I'm sure that helped. The carb seems to operate very well - I'm tentatively impressed. Tomorrow I plan to get the electric choke to work, check the A/F mix etc, and take it out for a run - weather permitting. Far from a recommendation, but so far (touch wood) everything looks, smells and operates better than expected.


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## Honeyharbour62 (Jul 15, 2018)

I have a retrofitted electric choke on my factory 67 QJet and works like a charm. Carb Junkies out of western Georgia is where I ordered it from.


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## Treozen (2 mo ago)

Honeyharbour62 said:


> I have a retrofitted electric choke on my factory 67 QJet and works like a charm. Carb Junkies out of western Georgia is where I ordered it from.


Yea - I bought a retrofit kit from a place here in Washington State (I always like it when I get something "local") but this was before I discovered the carb was actually a chevy design, rather than the stock Pontiac - so it didn't fit. I do think it would have been possible to modify the linkage, but the carb had several other issues as well.

Update is that I got the choke wired in, works great without any adjustment needed. I also set up the vacuum gauge and tachometer (from my timing light) and adjusted the A/F mix on the carburetor - which reminds me...why the heck are the Q-Jet adjustments so hard to get to...but I digress. Three different screwdrivers later and I think I have it set correctly - to be honest, it only needed a slight adjustment from the way it was set out of the box - probably the advantage an engine-tested Stage II set up. I ran out of time (and daylight) for a road test, but that's next. If that goes well, it will be on to replacing the brake booster, which I think is leaking.


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## 67ventwindow (Mar 3, 2020)

armyadarkness said:


> The big issue with the Qjet is cores. I tried too have Lars rebuild one for me, a few years back, and he refused all of my cores. He was adamant about it, too. Once the bases and tops are warped, and the throttle blade bushings are shot, and the internals have been drilled or epoxied, he wont touch them. I even tried to send him a new rebuilt from NAPA and Summit, but nope.
> 
> I'd kill for a Qjet... but the new Edelbrock is a big improvement over the old one, and Ive been running them so long that I can tune and rebuild them effortlessly. And... both of my 67's had Carters from the factory.










Will this work for a core? Its from my 86 C30. 


Treoz
Let us know how this carb goes. The Q-jet on my C30 is only slightly better than this core and is wired together. I need a fully functional carb in the spring.


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## geeteeohguy (Feb 2, 2008)

That's one of the most hammered Q-jets I've ever seen. I would look for something better for sure. 
The issue here and on other forums is that the guys that rebuild these old parts for other people have to stand behind them and guarantee them. Not something I would want to do. Also, the parts are OLD. The metal changes in some cases. It swells or gets brittle. Or the carb gets thrown out of an airplane like the one pictured above. The key is to find one that has not been hacked up, and that's about as easy as finding a '32 Ford that hasn't been hot-rodded. If I needed a Q jet and couldn't get one, I would run a Holley 700 or 750 on a 389-400. Not as economical, but no problems and powerful.


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## Treozen (2 mo ago)

67ventwindow said:


> Treoz
> Let us know how this carb goes. The Q-jet on my C30 is only slightly better than this core and is wired together. I need a fully functional carb in the spring.


Will do. Its raining hard today, so no road test. Frankly its a minor miracle the weather was nice enough to do anything, this has been a very odd, though appreciated, fall and early winter here in the PNW.


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## BearGFR (Aug 25, 2008)

The only significant difference between Pontiac and chebby QJets is the orientation of the fuel inlet. All Qjets are -at least- 750 cfm.

If you want to learn about them, there are excellent books available, including the one written by Cliff Ruggles.

Fuel can escape from them in two primary ways: 1) Evaporating out through he bowl vent (some models have a sort of vent seal that gets lifted open with throttle, but a lot don't) 2) Leaking jet well plugs in the bottom of the body, between the body and the throttle plate. Depending on how bad the leak is, it can also make the car run not-do-good.

Cheers,
Bear


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