Insert Knowledge here ------->

[hilandr452]

I am looking for an UBER, all encompassing, heavily detailed, bad a$$ web site that explains how every system of the quadrajet works and how to adjust them, from the mixture to the fast idle, to the various types of choke mechanisms. I want exploded views, step by step instructions and it needs to be worded for the morons of the world like me because I CAN'T FIGURE THIS THING OUT!!!!!!

Thanks,

Dan

[hilandr452]

BTW the carb I'm actually using is an edelbrock quadrajet replacement, 795 CFM, I'm assuming it's the same systems.

[68chevy68]

I have a good book around here somewhere. It has everything you need in it. I can't remember the name. Just do a search on amazon for it.

[jholley]

Send it out. No mere mortal can make them work right without professional help

[hilandr452]

I like to think I can do anything with a little instruction.

[Sport/Truck]

Originally Posted by 68chevy68

I have a good book around here somewhere. It has everything you need in it. I can't remember the name. Just do a search on amazon for it.

I've got that book your thinking of, and is full of good info. Amazon.com: How to Rebuild and Modify Rochester...

Originally Posted by jholley

Send it out. No mere mortal can make them work right without professional help

I used SMI.
s/t

[Lugnut64052]

Rochester Carburetors, by Doug Roe . . . is the shizzle on Q-jets. Get one, study it, you'll be a Q-Jet expert.

BTW, those Edelbrock Q-jets were made by Weber, but unfortunately they've been discontinued. They're identical to a GM unit and work excellent. I'm pretty sure Edelbrock still sells a rebuild kit for them though.

[hilandr452]

Thanks guys, I will get a copy.

[airdale94]

There's a mod for the idle cicuit in one of those books. There's a place in California that sells it as a kit. It really improves the the smog Q-jets. I would think the Ed's would already have it unless they're emission certified.

[sneakysnake]

Here is a little more info.
http://www.4wheelnoffroad.com/qjet.html

[suville]

Shawn Murphy Induction, I believe he is in Cal and he knows his schtuff on Q-jets, best carb goin for mileage and performance once theyre set up correctly!

[Wreckless_71]

Step One= Remove Quadra-Suck
Step Two= Install Holley

Just kidding, but that's what I would do. Like jholley said no mere mortal can get one of these running right. I've messed with em and I just can't ever get the buggers running right, but when they run right the run great...

[airdale94]

It's The Carb Shop. Here's an article on them. It's a Ed. Q-Jet they're modifying also.

http://www.hotrod.com/techarticles/e...ent/index.html

I had a 75 T/A that would run OK. Would run real smoothe after a rebuild then start to run so-so after some miles. Tried a new corect replacement from the parts store. Then put that kit in it. And it ran perfect, never had to mess with it again. It won't pass a smog check though with this mod.

The article talks about it down at the bottom of the page in the pictures.

I think it must be these guys.

http://www.thecarburetorshop.com/

They are in Mo. I was in the Navy in Ca. at the time. I was thinking they were in Ca. for some reason.

[RicksTrucks]

I ran across this guy, that seems to be an expert.

V8fastcars@msn.com

Cost for the Q-Jets is $160, and this includes a complete teardown, hot tank, detail, precision blueprint assembly, a good quality carb kit, a new NitroFill float, a new filter, a new choke pulloff, test-running the carb on my engine to assure performance, and return postage via USPS Priority Mail. If your carb does not need a choke pulloff, I will credit you the cost for this. I do not have capability to do the replating process like some of the commercial rebuilders, but then I don't charge $300, either... and my carbs run good. If your carb is corroded, rusty and looks like crap, it will be corroded, rusty and look like crap when you get it back – but it will be clean. I can do an acid dip to remove some corrosion, and I can do an Alodine (a.k.a. “iridite”) chemical conversion coat dip to bring some color back to the aluminum/zinc castings, but this will not restore any of the plating on the steel parts. If the carb needs other parts, such as linkage pieces, choke assembly, jetting components, etc., I charge my cost on these items in addition to the base fee. The carbs are supplied to you with a data sheet and installation instructions along with a new base gasket for installation to your engine. Cost for the Holley and BG carbs usually runs about $35 more due to the cost of the kit – I only use original Holley gaskets and kits, not any of the aftermarket cheap kits in these carbs. You MUST provide the fuel inlet line you will be using with any Holley or BG Carb, as I do not stock any fuel inlet lines: the carb cannot be tested and run without it. If you send me a Holley of BG carb without an inlet line, I will buy a line of my own choice and charge you for it. The aftermarket chrome plated lines are junk (they’re chrome plated copper hardware store lines), and they will leak – do not use them. Either use a stock GM inlet system for the stock GM Holley carb, or use one of the good quality aftermarket inlet line systems. I can build you a system if you need one for your Holley or BG. I do not need any line systems for the Q-Jets.



A note on hard-starting Q-Jets: A common problem on the Q-Jet carbs is “hard starting.” Owners report needing to crank the engine while pumping the gas pedal many times after the car has been sitting for a few days. The common diagnosis is that the “bowl plugs are leaky” and the carb is draining itself of the gas. Fact is that this is seldom the case. There are several issues that will cause the fuel to drain out of a Q-Jet bowl, and few of them have to do with the carb:

1. Modern Fuels. The fuel currently available has significantly higher vapor pressure than the fuels that these carbs were designed for. Since the Q-Jet float bowls are vented, the modern fuels will evaporate out the vent tube, dropping the float bowl level just enough so that the accel pump well will not fill with fuel (the Q-Jet accel pump does not get its fuel from the bottom of the float bowl: the bowl must be nearly full for the pump to function). If you have ethanol-additives and high vapor pressure fuel in your area, I cannot solve your Q-Jet hard-start problem with a rebuild.

2. Bad fuel pump. If you have a fuel pump with a slightly leaky check valve in it, the fuel standing in the column between the pump and the carb will drain back down through the pump after engine shutdown. Since the needle/seat in the Q-Jet is in the bottom of the float bowl, this drain-back action will actually siphon the fuel right out of the carb float bowl. I have seen many brand new fuel pumps with leaky check valves in them. I cannot fix a drain-back problem with a carb rebuild. You can check for a leaky checkvalve in your fuel pump by running the engine for a minute and then shutting it off. Wait about 5 minutes and then loosen the fuel line at the carb. If the checkvalve is good, there will be fuel pressure at the carb when you disconnect, and gasoline will spray out forcefully when you loosen the fuel line. If gas does not spray out and you only get a slight dribble of fuel, your checkvalve is allowing drainback.



Each carb I build is leak-checked overnight to assure that there is no fuel dripping out the bottom of the carb. If you have hard-start issues after rebuild, you have problems not related to the carb. Do not expect a rebuild to solve hard-start problems unless you have verified that there is fuel dripping out of the bottom carb plugs.



Stripped Threads: As an additional service on the carbs, I can correctly repair the stripped out inlet threads on the Q-Jets. I can do both the early 7/8-20 and the later 1”-20 thread repairs. I have procured all the tooling to correctly machine the inlet, tap it, and to install a stainless steel thread insert. I have built jigs and fixtures to assure that the new threads are square with the inlet nut sealing surface. This repair permanently repairs the stripped threads, and allows use of the stock in-carb inlet filter. Due to the cost of the tooling involved in this, I charge $50 for the thread repair. If you send me only your Float Bowl for repair, the total fee is $50. If you send me the entire carb for a thread repair only, I have to charge you for a carb rebuild as well, since the entire carb must be disassembled and cleaned in order to do the machine work.



Shaft Bushings: I can also install Q-Jet shaft bushings. However, keep in mind that new Q-Jets were actually very sloppy in the shafts. The need for shaft bushing installation is grossly over-rated, and very few carbs actually have enough shaft and plate wear to warrant this operation. If the shafts and throttle plate are worn enough to cause the primary throttle plates to stick and bind in the throttle bores, the bushings should be used. Otherwise, this is not necessary. If required, most carbs only need a single bushing installed on the driver’s side primary shaft; I have never seen excessive wear on the passenger side of a carb or on the secondary shaft. Fee for removal of the primary throttle shaft, reaming the throttle plate, installing the bushing, and reaming it to size is $50.



Commercially Rebuilt Q-Jets: Due to the age of the Q-Jets, more and more of the carbs have been subjected to a commercial rebuilder and sold through outlets such as AutoZone, NAPA, and Corvette parts suppliers. The commercially rebuilt carbs have serious problems due to modifications and shortcuts performed by the assembly line carb builders. There will be destroyed parts, bad parts, missing parts, and incorrect parts in any of the commercially rebuilt carbs. I highly recommend you avoid these carbs. If you have one and want it rebuilt, I will warn you that only about 50% of these carbs can be saved and made to run right due to drilled out passages and bad casting components. Most will require a significant amount of replacement parts, and I will not guarantee their performance on your application. If you want me to try to save one for you, I’ll give it a shot.

[thirdstreettito]

I know a few things about em, mainly just how to adjust idle.

[northerngmc]

All the QuadraJet Information I have found on the Internet

A listing of different sites..... good luck.

[Lugnut64052]

Wow.
I learned stuff from that V8fastcars guy just from reading his boilerplate.

Where is he and does he have a website?