External Devices; Fuel Pumps And Pressure - Edelbrock 1403-1413 Owner's Manual

1403-1413 Perf Series Carburetor Owner's Manual.qxd 3/31/2006 12:04 PM Page 8
The pump plunger is not driven directly by the throttle, but through an intermediate Pump Drive Spring
(4) that extends the duration of the "pump shot" past the time the throttle stops moving. The
Edelbrock Performer Series carburetor has an external pump lever with three hole locations for link
attachment providing three distinct pump delivery curves. This is further explained in "Calibrating The
Pump".
(3) Pump Jets
Pump
(2) Pump Discharge Ball & Weight
System
Figure 7
(4) Pump Drive Spring
(1) Inlet Check
(Lip Seal)

EXTERNAL DEVICES

The function of your Edelbrock Performer Series carburetor is also dependent on several external
devices; the fuel pump and air cleaner.

Fuel Pumps and Pressure

Avoid extremes in fuel pressure. At IDLE, there should not be any more than 6.0 psi; if the vehicle has
an adjustable fuel-pressure regulator, set it to 5.5 psi. With most fuel pumps the minimum fuel
pressure is encountered at high rpm and WOT. Fuel pressure should not drop below 2.0 psi. If it does,
a fuel pump with more capacity may be required. Note that some later model vehicles (the 5.0L Ford
is one example) have mechanical pumps that will give more than 6.0 psi at idle. The vehicle will
perform well, but may be prone to stalls on quick turns and stops with the clutch disengaged. If this
problem occurs, check the fuel pressure. If it is more than 6.0 psi at IDLE, it should be reduced
through the use of a regulator, such as Edelbrock #8190, or by creating a restricted by-pass bleed to
the fuel return line. Edelbrock Street Fuel Pumps are highly recommended for all Edelbrock Performer
Series carburetor installations.
Always use a filter, such as Edelbrock #8873 between the pump and carburetor. Note that a good
filter is large in area, so it may be able to transmit a significant amount of heat to the fuel. It is a good
practice to keep the filter away from heat and not allow it to come in contact with any part of the
engine.
8
Edelbrock Performer Series Carburetor Owner's Manual 8/94