FUEL INJECTION
FUEL PRESSURE REGULATOR
Operation Overview
The fuel pressure regulator maintains the required operating
system pressure of 39 psi + 3psi. A rubber-fiber diaphragm
divides the regulator into two separate sections-, the fuel
chamber and the pressure regulating chamber. The pressure
regulating spring presses against the valve holder (part of the
diaphragm), pressing the valve against the valve seat. The
combination of atmospheric pressure and regulating spring
tension equals the desired operating pressure. Any time the fuel
pressure against the bottom of the diaphragm exceeds the
desired (top) pressure, the valve opens, relieving the excess
pressure, returning the excess fuel back to the tank.
Fuel Pressure Regulator Test
Refer to the "FUEL PUMP TEST" procedure.
See "Fuel Pump Test" on page 4.9.
Fuel Pressure Regulator Replacement
The regulator is a sealed, non-serviceable assembly. If it is
faulty, the pump assembly must be replaced. Refer to the Fuel
Pump/Tank Assembly Replacement procedure.
4.12
FUEL FILTERS
General Information
NOTE: All EFI units utilize quick connect fuel lines.
EFI Engines use a non-serviceable, high-volume, high-
pressure, 30-micron internal fuel pump filter and a replaceable
10-micron, in-line fuel filter.
10 Micron Filter
Fuel Filter Service
In line filter replacement is recommended every 2 years of
operation or more frequently under extremely dusty, dirty
conditions. Use only the specified filter, and install according to
the directional arrows. DO NOT use an aftermarket filter, as
operating performance and safety can be affected.
Fuel Filter Replacement
NOTE: When replacing the fuel filter, wet the interior
of the new filter with gasoline before installation to
ensure high pump pressure doesn't tear the filtering
material.
1.
Relieve system pressure through the test valve in the fuel
rail before servicing.
2.
Loosen clamps and slide hose off the filter ends.
3.
Install new filter with arrow pointing to the fuel line
connected to the injector rail.