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Most Rochester carburetors are made of "pot metal".
Karl not know what that means, but it is not as strong as steel.
As a result, a notorious problem is stripped threads on the inlet.
There is a solution for this, but it is not pretty. There is a part available from
GOOD auto parts stores. It is an oversized, self-tapping, inlet fitting marketed as a
"HELP!" or "Perfect Parts" product.
You install it by forcing it to cut new threads into the fuel inlet.
It has been suggested by Doug Kichener that these fittings not be removed as there are likely
to be small metal fragments held between the threads by the new fitting. Removing the fitting
could permit these bits to get into the carb and catch in the tiny channels which flow fuel.
Not good.
This is a good time to install an inline filter into the fuel line.
A new line is probably necessary anyway as the new fitting can be more than an inch long, which will
be a problem for any factory original steel tubing!
Disabled EGR system.
Neither Karl, Rochester Products Division, or anyone else contributing to this site advocates
or in any way recommends altering or disabling your emission control equipment in any way.
That said, those whose EGR systems have "mysteriously" ceased to function have noticed that
their vehicle runs differently when EGR is non-functional.
The reason for this is that the EGR pump operates on manifold vacuum.
The primary metering rods are raised/lowered into the jet orifices by a piston that responds
to the manifold vacuum signal. When the EGR is inoperative, the manifold vacuum signal
available to the carburetor is very different from the conditions that the metering rods
and jets were designed for! This typically results in a lean condition, possibly including "surging".
The only real solution is to fix the EGR system.
Those incorrigibles out there who refuse to do this have to have their carburetor re-jetted
and re-rodded to correct for this. Best just to use rods and jets from a pre-EGR carburetor of
the same displacement.
Hopefully, Karl will be able to provide the appropriate part #s here in the future.
On a similar note, if the ECM (computer) is disconnected from an appropriate-year
Quadrajet, a severely rich condition results. Again the only real cure is re-rodding.
This is addressing a problem that Karl has had with his 1965 Rochester 2GC.
The symptoms are a periodically terrible idle that may have coincided with an instance of
WOT and may similarly go away after another instance of WOT. The motor will sputter and die
at idle and in fuel will contimue to flow from the discharge nozzles after the engine has
died. Sometimes fuel will leak through the throttle plate hinge shaft holes to the outside
of the carburetor and onto the manifold!
This has been diagnosed for me as contamination preventing the needle from seating properly
and causing a flooding or overfilling of the float bowl.
The cure for this is to rebuild the carb and replace or adjust the needle and seat.
Remove any debris from the float bowl and check or replace the fuel filter.
