New quadrajet set up
New air-gap manifold and custom/rebuilt q-jet. Sounds good but I still need
to set the timing on the distributor and the carb is tuned already. Hope
you like, nothing to fancy just a few revs and walk around...the Exhaust is true dual no x/h pipe and it has
cherry bomb glasspacks(3 inch)
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 de-bog your Quadrajet part 1
Sorry guys, I got the videos a bit out of order.
The Rochester Quadrajet has gotten a bad rap over the years, often called a
Quadrabog or Quadrajunk.
In fact, this is a great multipurpose carbureter once you understand how
they work and what not to do to them.
In this clip I introduce you to the Quadrajet and begin explaining the
theory of operation of these units.
Identifying Quadrajet vacuum ports
I always see a lot of questions about what various vacuum ports do on a
Here's a general guide that will point you in the right direction.
Remember that there were many different Qjets over the years and vacuum
port locations and number will vary. This video is representative of
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.
How to measure and adjust Quadrajet float level
I have had several requests for this, so here you go:
1. The airhorn has to be removed to do this, but the carburetor does not
have to be removed from the engine.
2. Some data says to measure from the toe(end that is opposite from the
hinge), some say 5/16 inward from the end, etc. I suggest following the
specs for your particular carburetor.
3. With the float in the raised position and the inlet needle lightly
seated, measure from the top of the float to the top edge of the carburetor
with NO gasket in place. If you have to adjust the float, bend at the area
that has the cutouts,
4, If you are experiencing flooding issues then it is an excellent time to
install a new needle/seat and float and that should cure flooding problems
that are not choke-related.
Combination valve bad, carburetor bogging
After doing the brakes -- the combination valve is bad-- the valve part is
seized. Troubleshooting the bogging...
Gapped plugs, plugged vacuum lines, check carb mounting bolts, distro shaft
has no wobble, the mechanical advance seems good (I guess-- moves freely),
accelerator pump squirts well