This article shows step by step how to modify your existing Rx3 or early model fuel tank to accommodate 2 x Walbro EFI Fuel pumps. We do not suggest this modification would be as good as an aftermarket setup. This is simply for those that have a conservative budget and are looking for cheaper alternatives. Firstly with this build you will have to purchase 2 x walbro fuel pumps. We sourced them on Ebay for $280 for a pair which came with all hardware. We then used 2 fuel pickups from a VS commodore, also available on ebay but we sourced from an auto wreckers for $40 for a pair.

We purchased 2 sender gaskets for $11 from holden the part number displayed below. This gasket was then used to mark out the holes on the tank and also make backing plates for the fuel pickup to attach to. For the backing plate we used a steel plumbing rings from Bunnings. And fitted it with 5mm Rivet nuts.

I think the biggest concern for most people choosing to use the standard tank, would be fuel surging in the tank and a fuel pump running dry and leaning out a motor. The RX3 tank has a simplified baffle system, we mounted each fuel pump on either side of the existing baffle, the image below displays where the baffle runs

The tank was emptied, and we chose to fill the tank with water prior to cutting the holes with a 50mm hole saw. There may be better ways to purge the tank of fuel, but we found this method sufficed. We then drilled the required holes again using the gasket as a template. We cut our backing plate in half so that it could be fitted into place, we then secured it using a high strength apoxy.

We then removed the fuel level sender from the fuel pickup, cut the pipes down and mounted the walbro pump using a stainless clamp, and solder / heatshrinked the power cables for the pump. We then mounted the pump to the fuel pickup with the clamps, hoses and fuel filter supplied in the fuel pump kit.

We then cleaned out the fuel tank, and mounted the fuel pumps into place. The pumps were tested prior to fitment to ensure in working order and that we had the correct polarity. The pumps were then mounted in the tank, and tested in the vehicle successfully.

Again we do not suggest this compares to custom build aftermarket fuel tanks, which have a more complex baffle system, this is simply a budget alternative, that allows the installation of high pressure efi pumps in an existing tank.