AEM HondaAcura Adjustable Fuel Pressure Regualtor 25303BK User Manual

ADVANCED ENGINE MANAGEMENT INC. 
2205 126TH Street, Unit A Hawthorne, CA. 90250 
Phone: (310) 484-2322 Fax: (310) 484-0152 
Http://www.aempower.com 
Part Number: 10-290 
© 2000 Advanced Engine Management, Inc. 
 
 
 
 
 
 
 
 
Adjustable 
Fuel Pressure 
Regulator
 
Installation Instructions for: 
Part Numbers
 
25-300 
25-301 
25-303 
25-304 
U.S. Patent # 6,298,828 
 
WARNING:
,! 
Due to the fact that this installation deals with your fuel system 
this installation is not for the mechanically...

This part is legal in California for racing vehicles ONLY and should NEVER be used on public highways. 
 
 
 
Congratulations!  You have just purchased the finest adjustable fuel pressure regulator for 
your car at any price! 
 
AEM billet aluminum adjustable pressure regulator. 
The AEM adjustable regulator bolts directly to the stock Honda or the AEM high volume fuel rail. 
It is CNC machined from 6061 T-6 aluminum. The fuel outlet port is tapped to 9/16-18 threads, 
which allows the use of several...

Bill of Materials for 25-300: 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Bill of Materials for 25-301: 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2  2-609  -6 to 7mm Barb Fuel Return Fitting 
1 2-611  Vacuum Fitting 
1 2-612  Spring Cap 
1 2-698  .250ORIFICE,BALLPRESSREG 
1 2-697  .175ORIFICE,BALLPRESSREG 
1 2-696  .1OrificeBALLPRESSREG 
1  2-8000  Fuel Pressure Regulator Top 
1  2-8100  Fuel Pressure Regulator Bottom (Inline) 
1 1-3007  Crush Washer 
1 1-3010  O-Ring 
6  1-2023  Socket Bolt, SS 8-32 x 5/16”...

Bill of Materials for 25-303: 
1 2-
610 -6 to 7mm Nipple 
1 2-
635 -6 Banjo Bolt 
1 2-
611 Vacuum Fitting 
1 2-
612 Spring Cap 
1 2-
698 .250 Orifice 
1 2-
697 .175 Orifice 
1 2-
696 .1 Orifice 
1 2-
8000 Fuel Pressure Regulator Top 
1 2-
8100 Fuel Pressure Regulator Bottom (Inline) 
2 1-
3007 Crush Washer 
1 1-
3010 O-Ring 
6 1-
2023 Socket Bolt, SS 8-32 x 5/16” 
1 1-
2021 Socket Screw, SS 10-32 x 1” 
1 1-
2022 Nut, Jam SS 10-32 
1 2-
300 Diaphragm 
1 1-
122 Spring 
2 1-
2045 Socket Bolt, SS M6 x1 x...

1  2-8000  Fuel Pressure Regulator Top 
1  2-8101  Fuel Pressure Regulator Bottom (Offset) 
2 1-3007  Crush Washer 
1 1-3010  O-Ring 
6  1-2023  Socket Bolt, SS 8-32 x 5/16” 
1  1-2021  Socket Screw, SS 10-32 x 1” 
1  1-2022  Nut, Jam SS 10-32 
1 2-300  Diaphragm 
1 1-122  Spring 
2  1-2045  Socket Bolt, SS M6 x1 x 12mm 
2  1-3016  Washer, SS M6  

WARNING!!!  Read and understand these instructions BEFORE
 attempting to install this product 
 
 
• Do not smoke while working on the fuel system. 
• Keep open flames or sparks away from your work area. 
• Be sure to relieve fuel pressure while engine is off. 
 
Note: 1990-1993 Honda Accord and 1992-2000 Honda Prelude require the use of the AEM Hi-Flow Fuel Rail 
P/N 25-104. The AEM Adjustable Fuel Pressure Regulator can NOT
 be used with the stock fuel rail on these 
applications. 
 
Note: Refer to...

The AEM adjustable fuel pressure regulator has been set to 40psi using a 
typical Honda fuel pump and a perfect running fuel system.  Due to the 
differences on vehicle fuel pressure on different applications it is highly 
recommended that you adjust the fuel pressure on your vehicle.  Refer to the 
last page of the instructions for the factory recommended fuel pressures. 
WARNING!!!  3) 
Stock fuel pressure regulator removal 
a)  Place a rag or shop towel under the fuel pressure regulator return line....

b)  When orifice changes are to be made, remove the fuel pressure regulator using the steps in section 4 in 
reverse order.  When this is completed, remove the six bolts from the top of the fuel pressure regulator and 
use a 3/8” socket to remove the orifice in the regulator and replace with a different size orifice. 
i)  When removing the six bolts from the top of the fuel pressure regulator a 9/64” allen key should be 
used. 
(1)  Torque to 24 lbf-in. 
(2)  There is a constant pressure applied to the...

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Regulator Part 
#
 
Straight or 
Angle Return
 VehicleYearModelRec. Fuel 
Press 
25-300 Straight Integra 94-2000RS, LS, GS40-47 PSI 
25-300 Straight Integra 94-2000GSR, Type-R48-55 PSI 
25-300 Straight Accord 88-89LXI, SEI36-41 PSI 
25-300 Straight Accord 90-91All35-41 PSI 
25-300 Straight Accord 92-93All40-47 PSI 
25-300 Straight Civic 92All40-47 PSI 
25-300 Straight Civic 92-95All40-47 PSI 
25-300 Straight Civic 99-00SI40-47 PSI 
25-300 Straight Del Sol 93-95S,...