New Carb

[N PRGRES]

I have a TA card and it's junk.  I got it from a guy and they basically gutted the throat of it out for whatever reason.  We have a local guy who is super good with the quadrajets and even he can't get it to really work as it needs to.  So, I want to
verify that the carbs on the TA is different than a regular quadra jet, and where the best place is to get one, or if I should just junk the carb and go FI

[b_hill_86]

I guess that depends on your definition of a regular quadrajet. Cliff Ruggles no longer does rebuilds but he may sell complete carbs. He can certainly answer any questions you may have. You could try to reach out to him or check out his forum. There are lots of helpful, knowledgeable people there. https://cliffshighperformance.com/simplemachinesforum/index.php

[Oldsschool79]

From what I learned when I restored my T/A the quads differ on models and engines. Best to use the ID number engraved on the housing if its original.  I bought one remanufactured a stage 1 and it works well. Would love to go to the stage 2 performance model. Seems like the engine wants to go for more top end.

[Wallington]

Likewise, saying stage 1 and 2 doesn't mean much unless compared to original engine and carb and engine work requirements. And most don't. That's why Holleys exist.

[nUcLeArEnVoY]

From what I learned when I restored my T/A the quads differ on models and engines. Best to use the ID number engraved on the housing if its original.  I bought one remanufactured a stage 1 and it works well. Would love to go to the stage 2 performance model. Seems like the engine wants to go for more top end.

Indeed, Quadrajets are heavily application-specific and any given casting number assigned to any given engine or engine family will have different jet sizes, different air bleeds, different metering rods, different float levels, etc. They're emissions carburetors and were tuned/jetted very lean to provide the best economy, which leaves very little margin for error in tuning them on a performance engine, unlike a Holley which is very forgiving because they provide ample fuel. This is why invasive modification is needed for Quadrajets such as opening certain air bleeds or fuel orifices to with drills to run these carburetors on performance engines, especially with camshafts that have a lot of overlap that lower your engine vacuum. But it can be done. It's this unfortunate fact along with their many, many, many, many points of adjustment that give Quadrajets sort of a love-them-or-hate-them reputation and they're often misunderstood. Tuned right, they are amazing and reliable carburetors.

Oldsschool has a good idea in that I would get the same carb you have now, but unmodified and take it from there. And it's a good opportunity to learn to do it yourself - just open the thing up and get to know it. The first dive in is intimidating, but there are so many step-by-step walkthrough videos on YouTube now that will give you a comprehensive breakdown on how to dissassemble and reassemble the carb that it becomes second nature. I've opened up my QJet so many times now that it's practically muscle memory putting it back together, and I have it tuned well enough for just normal cruising and a good-operating choke, but I do have a WOT bog I need to correct. Probably just the secondary door tension.

As for modifying them for a performance engine, Cliff Ruggles' book comes with doznes of "recipes" based on your engine and its modifications that will outline how to modify your QJet so that it can be made to work.

[5th T/A]

I have a TA card and it's junk, or if I should just junk the carb and go FI.

I vote for getting the quadrajet working. As others have said, get a used Pontiac carb or two and start playing with them.

Properly installing a EFI system is no small task. You will spend a fair amount of time and money. If you don’t do it right it can present it’s own problems. Yes EFI is great for frigid winter startups and cold drivability. Also nice if you drive your car in different elevations. I don’t do either of these things. On my car I had a MAP sensor fail shortly after I got the car running. My EFI is supposed to have some limp home features, but it refused to even start. I can’t image this happening with a carb.

This probably wouldn’t be a factor for most people, but I miss the sound of the big secondaries opening up with a quadrajet, evenly sized primary and secondaries have a different sound.

[N PRGRES]

Thanks Guys, I thought I explained it in the first post that this is NOT the original carb so I am not sure if getting a casting number will help or not.  The engine is not heavily modified.  Its a mild cam, some head work and bored .030 over, but thats about it.

As far as buying a few and messing with them, not an option, I know my limitations and messing around with the internals of a carb would drive me insane, same reason I don't do engine rebuilds, too much ADD lol 

The carb runs well other than when I get on it, it wants to just bog way down.  It did the same thing on the dyno.  We replaced the fuel pump with I believe a 100 GPH pump but that's been awhile. I am almost wondering now that I am typing this if it sitting for so long with ethanol fuel maybe messed it up and it just needs gone through again. 

Even without a coke, starting and idle has never been an issue.  Maybe this winter I'll have it pulled and gone through again.

[5th T/A]

Dave, several years ago I had a conversation with Cliff Ruggles and I remember him saying that all Pontiac quadrajets were pretty interchangeable and could be tuned to work for your application. It’s been years since I have really played with quadrajets but, the spring loaded flapper above the secondaries is adjustable. If you increase the spring tension it will not open until the engine has enough vacuum to handle it. This is pretty easy to adjust and may eliminate your bog. Something a carb guy could do, or work with you.

[N PRGRES]

Dave, several years ago I had a conversation with Cliff Ruggles and I remember him saying that all Pontiac quadrajets were pretty interchangeable and could be tuned to work for your application. It’s been years since I have really played with quadrajets but, the spring loaded flapper above the secondaries is adjustable. If you increase the spring tension it will not open until the engine has enough vacuum to handle it. This is pretty easy to adjust and may eliminate your bog. Something a carb guy could do, or work with you.

Thanks.  I seem to recall in my diminishing old memory that the TA had a special carb design or something along those lines.  I wasn't sure if that was an old wives tale or fact.