Fuelab 56501 High Flow Fuel Pressure Regulator - Manual (Page 3)

4. Apply light oil onto the threads of the Adjustment Screw. Small amounts of air leakage in the adjustment
hardware may be present during operation. This is a normal operating condition. Thread the Adjustment
Screw by hand until a slight tension is felt, this position is the minimum pressure setting. Do not tighten screw
any further. Pressure is to be adjusted later in these instructions. Install the Flat Washer, then the Jam Nut.
Tighten the Jam Nut hand tight for later adjustment.
5. Install Bracket to regulator using supplied Bracket Screws and Bracket Lock Washers. Tighten Bracket Screws
between 25-40 in·oz of torque (snug, do not over tighten screws).
6. Install the fuel fittings (not supplied). The threads used on these Fuel Ports are not tapered or pipe threads.
Do not use Teflon

thread tape or thread sealant on these threads, as this can cause leakage or introduce
debris into the fuel system. Fittings to be used with these style of ports require use of the enclosed–906 O-
rings for proper sealing (reference diagrams, below). Use light oil to lubricate the O-rings just prior to
installation. Install the O-rings onto the fuel fitting first. Position the O-ring in the thread relief of the fitting as
shown in the diagram, below. Thread fitting into regulator and tighten between 5 and 15 ft·lbs of torque.
7. Use Teflon

tape or thread sealant on all 1/8”-NPT fittings to be used for the Gauge Port and Pressure
Reference Port (see diagrams, below). Install fittings or plug as required. If pressure reference port is not
plumbed to the intake manifold (for typical EFI applications, port is plumbed to the intake manifold) then install
the Barbed Fitting (supplied) and allow fitting to vent to atmosphere (do not plumb or plug port).
8. Install regulator assembly into vehicle, fastening the bracket to the vehicle. Attach fuel lines, Gauge Port line (if
external pressure gauge is used in application) and Pressure Reference Port line (if applicable). Boosted
applications (such as turbo or supercharger) will require a hose clamp on barbed fitting to prevent hose from
coming loose. Use of –3AN or –4AN fitting and line can also be used as a substitute to the barbed fitting.
9. Inspect fuel system for any contact of fuel lines or wires with other components that can cause chafing or
rubbing. Secure all components and fuel lines.
10. Connect the vehicle’s battery. Turn on fuel pump (typically by bypassing fuel pump relay) without engine
operating. ECU or engine management computer may be controlling the relay. The ECU may only operate
pump for a few seconds each time ignition switch is set to on. The pump will have to operate several seconds
(30+) to prime and drive air out of the fuel system. Fuel system pressure should read about 25 PSIG (use an
external gauge for adjustment if a permanent gauge is not used). Inspect vehicle for any leaks. Turn off fuel
system and repair any leaks that may be present before continuing.
11. When adjusting pressure, be sure that fuel pump is operating to monitor pressure. Increase pressure by
rotating adjustment clockwise. Do not thread Adjustment Screw past jam nut within 1/8”. Over tightening the
adjustment screw can damage the regulator. It is recommended to use a “baseline” pressure reference when
adjusting the pressure (adjusting the pressure with engine off or Pressure Reference Line unhooked). The
vehicle’s engine may not produce consistent vacuum during idle to have repeatable readings.
12. After final adjustment of fuel pressure, tighten Jam Nut. Road test vehicle, and retest pressure upon return to
ensure accurate adjustment.
for gauge or fitting)
(Not Supplied)
-910 O-ring Shown,
Example -10AN
Install with Cup
toward Regulator
-910 O-ring
Example -10AN Port Style Union
Front
(Logo)
prior to Fitting
Fitting Shown (Not Supplied)
Gauge Port Plug
(can be substituted
Port Style Union
Installation
1/8"-NPT Gauge Port
-10AN Return Line Port
Fitting Shown
Example -10AN
Port Style Union
Fitting Shown
(Not Supplied)
105020621-1, No Rev Sheet 3 of 4
substituted with other fitting)
(3X) Bracket Screw
Adjustment Screw
Jam Nut
Number
Typically, for EFI) flat Washer
(Engine Vacuum
Identification
Unique Serial
1/8"-NPT Pressure
Reference Port
(1/8") Barbed Fitting (can be
(3X) Bracket Lock Washer