Walbro Fuel Pump
John B. Lunsford
Asheville, NC
Navigation catagories...

Performance Modifications
»Build Details
»Crank Comparisons
»Adjustable Fuel Pressure Regulator
»Walbro GSS-315
»Turbo Information
»Performance Techniques Upgrade
»Blitz BOV
»PVC Intercooler Pipes
»Intercooler Fan
»Dual Stock Intercoolers
»Blitz SSBC Boost Controller
»HKS Turbo Timer
»Timing/Error Code Interior Switch
»Lexus AFM
»JBLMk3 Turbo Outlet Elbow
»RPS Stage III Clutch
»Fluidyne Radiator
»Aux AC Fans Override
»Battery & Coolant Res Relocation
»Power Stop Cross Drilled Rotors
»Intercooler Ice Cage
»Engine Bay Heat Escape

Miscellaneous Information
»87 Restoration
»Misc Info
»Misc Part Numbers
»Blown Head Gaskets
»ECU Diagrams

»11/10/2002 Dyno
»05/20/2004 Dyno
»My Videos
»Friends Videos
»Other Videos

Anything over 12 psi of boost calls for a fuel pump upgrade. My pick is the Walbro. See the fuel pump test chart (bottom of the page). The installation is very straightforward and simple.

pump kit
Parts included with the Walbro GSS-315/341
Pump, filter, instructions, 4" section of fuel hose with stainless clamps, small washer, rubber cover, two wire crimps, and wiring connector.

With the fuel tank out of the car, remove the stock pump. It is all very simple and there is no trick to it. If you have a TSRM, Haynes manual or something similar you can get complete details there.

large tank diagram
Just unbolt the seven Phillips bolts and lift the pump right out.

fuel lines at tank
This is the ideal time to replace the fuel filter as it is extremely hard to do with the tank in place. While the tank was out and the car up on ramps, there was plenty of room to sit underneath and figure out a good way to relocate the fuel filter. I relocated mine to the inner fender behind the passenger side back tire. There it is secure and easily accessed.

The Walbro is smaller than the stock pump and has a different electrical connector, so you will have to cut the factory wires and crimp the ones that came with the Walbro to them. The black wire on the Walbro connector connects to the ground wire that rivets to the pump bracket inside the tank. The red wire crimps to the wire that comes through the top from outside the tank. Make sure you tie the pump to the bracket with a zip tie or something to hold it in place. I didn't have any zip ties so I just used a piece of 12 gauge solid copper wire with gasoline/oil resistant coating and twisted the ends together with pliers. After about six months, I took this pump out and put it in my 91. It was still held perfectly in place by the copper wire with no play. I don't think zip ties would have held up this good.

pump on hanger 1 pump on hanger 2
When you install the Walbro pump, you must remove the restriction at the fuel return line after the stock fuel pressure regulator. It is the 'U' shaped piece bolted to the block under the manifold. The fuel line goes from the fuel pressure regulator down to this U shaped section of metal tubing and then to another rubber gas line. You can either drill out the end of the metal tube or just bypass it with a metal vacuum/gas line coupling. Make sure you use clamps. This restriction will cause a rise in fuel pressure of about 6 or 7 psi which will probably cause your car to run too rich. I just ran my lines from the hard line from the tank directly to the fuel pulsation damper, then from the fuel rail where the old regulator was to the new AFPR and then out the bottom of the regulator to the hard return line. It takes a little fabrication and a few fittings but gets rid of some clutter and kind of cleans up the engine bay a little. The next thing to do is install a new Adjustable Fuel Pressure Regulator ( AFPR). If you plan on running much over 12 psi, it is a must.

Back to Top
For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.
John 3:16

This site was built and is maintained by John B. Lunsford.
If you experience any difficulties or have any site specific questions or comments, please email me at Webmaster.
Please direct all other email to John@JBLMk3.com.

Valid XHTML 1.0 Transitional PHP Valid CSS!