Going to take apart what I just bought

[AZracer]

Hey guys I have a stock 67 GTO and trying to get it to run right. The carb it had on it was total crap. I bought Cliffs book and read it front to back and back to front. I am starting to understand the Quadrajet now. I have mostly worked on Holly Dominators. Anyway I bought a carb from Carbs Unlimited and they said they could fix me up with a what I needed. The number on the carb is 17054909 I was told already that the air horn is wrong but I don't know. In any case I'm going to try and get it to work. Any tips would be Appreciated.

Pat

[Cliff Ruggles]

Yes, that's not the correct airhorn, not even correct for that center section without modification to one part or the other.....Cliff

[AZracer]

Thanks Cliff for responding. So is a hopless case or can I modifly it in house the get it to work. Do I need to disassemble and post more pictures?

Pat

[AZracer]

Well I decided just to put it on the see what would happen. I started right up and idled OK responds good to light acceleration. The air flap is being held tightly shut by the pull off and choke is held open about 1/4 inch. No leaks. I can't find ported vacuum. I don't think the vacuum advance works anyway because when I hook it to manifold vacuum the idle stays the same. I will warm it up and go punch the throttle and see if it's as bad as the other carb.

Pat

[omaha]

One way to check the vac advance would be with a hand held vacuum pump like a mighty vac. If the vacuum canister IS bad, you wont be able to hold vacuum on the gauge of the pump. Another good thing about this is you can see where the vac advance (kicks in) on the gauge if the vacuum canister IS goood.(visually with the cap off) Like if the vac advance kicks in at 22 inches  and the engine only has 16 inches of vacuum at idle, then hooking the dist to a engine vacuum source will do nothing while the engine is idling. all depends. the issues you have with not finding the dist vac port may be due  to the mismatch situation with the top/main casting. I would think  that some investigation will be necessary. 

[AZracer]

Thanks Omaha, This car is pretty original and many things don't work so the advance could be rusted up and frozen. I set the timing at 8 degrees. I need to know what the total timing should be. I don't know if there are many different units that make the total timing more for race. I'm just a stock 400 Pontiac.

Pat

[Cliff Ruggles]

That airhorn can be made to work with that center section, it only requires one pair off upper idle airbleeds.  The main airbleeds wouldn't be the right size either, but all of those items are easily changed......Cliff

[AZracer]

Thanks Cliff,

 I'll read your book some more about the upper idle bleeds and main air bleed size. I'm guessing I should use recipe #1 to size them.

and I think it is idling richer than before.
Pat

[AZracer]

OK I took it around the block and I had no hesitation at all. I even laid rubber when it hit second gear!!! So things are better but I want to make perfect. So I'll need to go through it and hit all the fine points.

Pat

[AZracer]

That airhorn can be made to work with that center section, it only requires one pair off upper idle airbleeds.  The main airbleeds wouldn't be the right size either, but all of those items are easily changed......Cliff

Cliff so are you saying I have two upper idle airbleeds now and I need to disable one pair?

Thanks Pat

[Cliff Ruggles]

I'd take it apart and see what you find, they may have already made modifications to it......Cliff

[AZracer]

Well it is not right when I start it up. The other carb the one thing it did do very good was start and idle even without a choke, but had a big hesitation at part throttle and full throttle just die. This new one has no hesitation anywhere and is strong at WOT. It does not respond much when I turn the idle mixture screws is harder to start and has a ruff idle. I am going pull it off and check everything to your recipe # 1 Plus check the idle circut in the old one because the engine liked it.

If indeed it has two upper idle bleeds which one should I disable? Or doesn't it matter. Can I buy individual parts from you or do have to buy a whole kit if I find a problem.

Thanks again, Pat

[Cliff Ruggles]

Most likely you will find the smaller fuel inlet seat, and wrong pump spring (coil binding) on the pump.  Difficult to say what you'll find for upper idle bleeds.  Pontiac used them in the airhorn for the early carburetors, many others had them in the main casting.

Doesn't sound like it's got enough idle fuel either way.....Cliff

[AZracer]

I don't think I have any upper idle bleed. !!!

Pat

[AZracer]

Airhorn