1995 3000GT: Defi Fuel Pressure Sensor Installation

• Why Do I Want To Do This?

  • There is no stock fuel pressure gauge.
  • Maintaining proper fuel pressure is critical in tuning your engine. If you can play with fuel maps and corrections all day, but if you have fuel pressure problems, you may still not get your car running how you'd like it to be running.
  • When running stock fuel and stock turbos at 14psi, I noticed a lean condition in the upper RPM range in my VR-4. I traced this to a loss of fuel pressure (by as much as 15psi!), which seems to be caused by a drop in voltage at the the fuel pump. Without a fuel pressure gauge, I wouldn't have been able to quickly determine the source of my lean condition.




• How Long Will It Take Me To Do This?

  • Plan for 2-3 hours.




• Anything I Should Do Prior To Attempting This Procedure?

  • Remove your battery.
  • Remove your washer fluid tank.




• What Mitsubishi Parts Will I Need?

  • None




• What Other Parts Will I Need?

  • Defi Fuel Pressure Sensor
  • 1/4" NPT Female Tee Fitting
  • 1/4" NPT to 1/8" NPT Bushing
  • (2) 1/4" NPT Male Barbed Hose Fittings
  • (2) Small Hose Clamps
  • Teflon Tape




• Where Can I Get the Stuff To Do This?

  	Part	Company/Contact	Part Number
  	Defi Fuel Pressure Sensor	MVP Motorsports	Defi LinkII or BF Series Fuel Pressure Gauge
  	1/4" NPT Female Tee Fitting	McMaster-Carr or any Hardware or Auto Parts Store	4429K251
  	1/4" NPT to 1/8" NPT Bushing	McMaster-Carr or any Hardware or Auto Parts Store	4429K411
  	1/4" NPT Male Barbed Hose Fittings	Hardware or Auto Parts Store	N/A
  	Small Hose Clamps	McMaster-Carr or any Hardware or Auto Parts Store	5388K16
  	Teflon Tape	Home Depot or any Hardware or Auto Parts Store	N/A





• What Tools May/Will I Need?

  • Wrenches (didn't note sizes when I did the installation)
  • Tubing/Hose Cutters or Really Sharp Scissors
  • 1/4" Socket with Ratchet or Flat-blade Screwdriver

The Procedure

	Lay Out Parts
	Gather all your parts and make sure everything will fit together.
	Assemble Sensor and Fittings
	Assembled unit - use teflon tape to ensure a good connection.
	Install Sensor Assembly
	After relieving fuel line pressure (see fuel filter instructions for details), carefully cut the high-pressure fuel feed line using your tubing cutters. This is the line that goes to the FRONT fuel rail, not the rear one. You can also identify this hose as it is the one that connects to the top of the fuel filter. Have rags/towels availble to catch any fuel that runs out of the newly-cut hose. You want this cut to be as clean as possible to reduce the possibility of leaks. Leaks in the fuel system are not to be taken lightly as it could easily cause an engine fire. Depending on how much room you have in the area of the fuel lines, you may want to cut out a 1" section of the fuel hose so that the new connections do not extend the overall length of the hose too much. I didn't need to do this. Slide the ends of the hose onto the barbs in the Tee fitting and attach the band clamps securely.