Mark71

Well, I finally have some time to work on my car again... Apparently over the long sleep it has had, the previously "rebuilt" carb has had some issues. It was stored dry, but...

I pulled it off and put a back up Q-jet on it that I had rebuilt last fall. It runs with that Q-jet, but not well. It is having a lean backfire under part throttle and just generally not running well at all. I think it is just waaay out of tune. I know someone drilled the primary plates on it and it has a really soft power piston spring... My car has a stock cam, which produces a lot more vac than whatever it was on before.

Is there a "reasonably priced" tuning kit available for Q-jets of the pre 74 era? Everything I have found is around 200. That's a bit much considering I can get a brand new carb from Summit for around 250 or spend a few bucks more an get something really solid.

I'd like to keep a Q-jet on it, but I'd rather not spend quite so much on a tuning kit, especially because I've never tried to tune one.

Olds64

Go to your local auto parts store and get a rebuild kit for your Qjet. It should be less than $30. It will have everything you need to rebuild the carburetor except throttle plate bushings and new floats. A carburetor that is 30+ years old should have the throttle plate bushings replaced; however, I've rebuilt plenty of Qjets without doing that step and they run much better after a rebuild.

tru-blue 442

+1. The rebuilt one that you want to use
probably just needs a new accelerator pump.
They tend to dry out, and get hard.

Sometimes you can pull the top off one
without damaging the upper gasket. I have
had sucess doing that, but you have to be
careful. I used a razor blade.

Octania

Summmit has a power piston selection for under $20 I think, look into that plus your std issue rebuild kit. Shop rockauto.com, amazon, and feepay.

Mark71

Yeah, I am actually going to get one of those kits that use valve guide bushings to rebush the throttle shaft. Apparently a k-line 1918b is the right bushing...

The original one I have has a sticker on it that just says "rebuilt", but I am not sure I want to use it. How they rebuilt it then is a little funky - they've replaced most of the threads with helicoils, ground down the holder for the float and replaced it with a strange "hook" mechanism, pressed in some odd-shaped bushings into the secondary bores, etc. etc. I can't say I understand the mods they made...

That's why I am thinking of tuning up my backup instead - it's in much more original shape internally and is very close in terms of age (72).

I looked there, but I wasn't able to find one. Any idea what the part number(s) is / are?

Edit: Can I use a set like this one to tune a normal (non-Edelbrock) Q-jet? http://www.jegs.com/p/Edelbrock/Edel...53848/10002/-1

Thanks!

Olds64

If the fuel inlet in the front of the carb has already been done that is good. I stopped using my Qjet because it started leaking from the fuel inlet. Helicoil kits can be bought but you need special tools to do it correctly. FWIW, I've seen folks remove the fuel filter from the fuel inlet and JB weld the fuel inlet to the body of the carburetor to prevent fuel leaks. It looks ugly but it works.