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In-Line Secondary Fuel Pump

Problem:

    After installing the gt35r I started to get leaning out problems towards the top of the gear when pushing boost above 20psi.  (The data logs can be seen in the link below.)  I did not want to destroy my engine, so I needed to upgrade my fuel system.  Since I already had a Walbro 255lph HP installed in the fuel tank, I thought I could get away with just upgrading the lines and fuel filter.  After further thought, I decided that I would just spend the little extra money on a secondary in-line fuel pump and be done with the problem for good.

    Considering the feed line from the inside the fuel tank is roughly -6AN this maybe a little over kill, but I settled on -8AN supply lines feeding a Walbro 255lph in-line fuel pump.  (If I was to do this again in the future, I would just stick with -6AN supply line.)  A Golan fuel filter cleans the fuel down to 10 microns.  The 1g fuel rail is tapped for 3/8" NPT so a 3/8" NPT male to -8AN male adaptor can be installed.  The Buschur/SX fuel pressure regulator is installed on the 1g fuel rail in the stock location.  From the FPR a -6AN return line runs down the the stock fuel supply line along the firewall.  The stock fuel supply hard line carries the fuel back to the fuel tank.  At the tank I cut the end of the rubber supply line off, so I could easily slip the rubber hose over the return feed line nipple on the fuel tank and clamp it down with two hose clamps.

 

  Data log graphs of problem before and after being fixed.

 

Installation Overview

 

Detailed Pictures and Description of Installation

 

Complete parts list for upgraded fuel system.

 

Fuel system before upgrade:

-Walbro 255lp HP in-tank

-stock lines

-new stock fuel filter

-1g fuel rail

-FIC 950's injectors

-Buschur/SX FPR

 

Fuel system after upgrade:

-Walbro 255lp HP in-tank

-8AN S/S supply line

-Walbro 255lp in-line

-Golan fuel filter

-1g fuel rail

-FIC 950's injectors

-Buschur/SX FPR

-6AN S/S return line to

-Stock supply hard line used as return line