Everything you wanted to know about automatic chokes but were afraid to ask
I've noticed many people drive vehicles with inoperative chokes. Even though chokes can be intimidating, repairing and adjusting them actually is very simple.
So, stop pumping that accelerator and follow along as we look at how chokes work and how to repair them.
How to debog your Quadrajet part 3
In the first two videos we looked at operational theory of the Quadrajet. In this episode we'll explore a couple mistakes the home mechanic often makes in an effort to improve the performance of this unit.
How to adjust carburetor mixture screws
Here's how to find and adjust the mixture screws on your carburetor.
Note that metering-block style carbs such as Holley and Demon more often have one or 2 mixture screws in each metering block depending on the number of venturi. Also those may not be located at the bottom of the carb as in factory carburetors.
How to adjust Quadrajet/Dualjet fast idle
Quadrajet/Dualjet Rochesters have a fast idle adjustment screw that is separate from the base idle screw.
Here's how to locate it.
Note: Ever since Charter "fixed" my internet and cable after the lightning strike, it hasn't worked right. Go figure. So, if you see this posted then I was finally successful in getting a video uploaded.
See 1976 Chevrolet pickup with Rochester quadrajet upgrade on SBC 350 V8. We removed the hood, mounted a camera looking down on the air horn, and took it for a spin, running wide open on an uphill grade. See how the secondary air valve responds to rpm drop at each upshift of the THM. Also included is a smoking burnout.
Decoding a Rochester Quadrajet part 1: The name
Rochester Quadrajets tend to mystify people because of the various model names assigned to them by GM.
Add to that a redesign in the '70s and the confusion only grows.
In this video we'll learn the different model names and also how to differentiate between early and later-model Qjets. Enjoy!
How to de-bog your Quadrajet part 2
The Rochester Quadrajet has gotten a bad rap over the years, but it's actually an excellent carburetor once you understand how they work.
Often referred to as "Quadrabog" or "Quadrajunk", many of the issues these units suffer stem from neglect, or "modifications" that do more harm than good.
Being a spreadbore, air-valve secondary design, the Quadrajet is capable of flowing 750 or 800 cfm of airflow, eliminating the need to buy different carburetors when your set-up changes. In addition, the small primaries make for great drivability and fuel economy.
In this clip, I'll discuss theory of operation on the secondary side, since that's where most problems arise. So, leave your preconceived notions at the door and let's see what makes these carburetors tick.
how to minimize engine bog with a Quadrajet carb
this is to minimize engine bog when the pedal is to the metal. do not over tighten, very small spring...you want to try 1/4 turns or 1/2...q-jets are good if tuned properly. also when you are tightening screw it will have tension on it so keep the screwdriver firm. 1986 gmc sierra single straightpipe to cherrybomb. you will need a small flathead screwdriver and a 3/32 allen key. be sure not to tighten to much or else your vacuum secondary flaps wont open.
Edelbrock Carburetor Installation and Troubleshooting Part 1 - Before You Start
Edelbrock Performer Series and Thunder Series AVS carbs are the most reliable, trouble-free carbs available today, however proper installation and tuning will ensure that you get all the performance you want from your engine. Whether this is your first carb installation or you've been doing it for years, this video shows you how to install the carb on a variety of intake manifolds, how to check linkage and vacuum line hook-ups, set the idle speed and mixture, and help you diagnose any potential trouble spots. In some cases, additional tuning will be required to calibrate the carburetor for your unique requirements, and this video shows in detail just how easy it is to get the carb perfectly "dialed-in" for your combination.