INSTALLATION INSTRUCTIONS
®
IMPORTANT: This regulator must use a fuel return line. The fuel return line runs between the fuel
bypass port of the regulator and the fuel tank. Fuel pressures cannot be adjusted if the fuel return
line is absent.
PARTS INCLUDED IN THIS KIT
1 Fuel Pressure Regulator
1 Bracket
2 Bracket Mounting Screws
2 3/8" NPT Pipe Plugs
2 AN-8 Fittings
2 O-rings for Fittings
SPECIFICATIONS:
Port thread sizes: 3/8" NPT and AN-8
Adjustment range: 30-100 PSI
Fuel Application: Gasoline and Alcohol/Methanol
GENERAL INFORMATION
Mallorys 4305M regulator regulates fuel pressure between high pressure
fuel pumps and fuel injection systems. The regulator is recommended for
Mallory COMP PUMP
®
60FI, 110FI, or any fuel injection pump designed to
produce 30-100 PSI.
The 4305M regulator is a return style fuel pressure regulator. The excess
fuel and fuel pressure is sent back to the fuel tank through the fuel return
line. The fuel return line runs between the fuel bypass port of the regulator
and the top of the fuel tank. The fuel tank must have provisions for a fuel
return line.
This regulator is equipped with a vacuum/boost compensation port (brass
barb fitting) that can be used to momentarily decrease fuel pressure
(vacuum compensation) at idle and part throttle, or increase fuel pressure
under blower boost (boost compensation). While it is not necessary to
connect a hose to the vacuum/boost compensation port, it may be
beneficial in some cases. However, the small plug on the barb must be
removed before use.
You can mount the 4305M regulator at any angle. For maximum
efficiency, mount it as close as possible to the fuel injection system. DO
NOT mount the regulator on or near exhaust manifolds. A bracket is
provided for convenient mounting.
ADJUSTMENT SCREW
JAM NUT
REGULATOR CAP
REGULATOR HOUSING
INLET PORT FROM PUMP (AN-8)
BRACKET MOUNTING HOLES (2)
FUEL BYPASS PORT (AN-8)
VACUUM/BOOST
COMPENSATION PORT (3/16"
O.D. BRASS BARB FITTING)
OUTLETS TO INJECTION
(3 PLACES, 3/8" NPT)
UNUSED PORTS MAY BE
PLUGGED OR USED AS
GAUGE PORTS
FORM 1527 (REV. B) 06/01
COMPETITION
FUEL PRESSURE REGULATOR
FOR FUEL INJECTION
PART NO. 4305M
