DIY: Walbro 255 LPH Fuel Pump Install on S14
For those of you requiring more fuel for turbo applications, Walbro 255 lph (liters per hour) offers a good solution to help ensure that your engine doesn’t starve when your stock pump can’t deliver enough fuel to your oversize injectors. For stock applications, it will not get more fuel into your engine as the FPR (fuel pressure regulator) controls the amount of fuel permitted to enter injectors. So adding this fuel pump will not yield any magical horsepower to a stock factory car unless your existing pump is failing and this might help restore the response of fuel delivery.
Important: Safety first – goggles, gloves (better than the ones I had hopefully – these were coming apart after few minutes and required a lot of handcream afterwards), and fire extinguisher on hand. Work outside / ventillated area.
It’s best if you do this with tank filled to half or less. This avoids spills and potential hazard.
First remove the cover in the trunk – it uses clips to hold it in place…
Use a wooden block (mine is a triangular one that has barely enough room to fit into the panel access hole) and rubber mallet to gently tap turn & remove the plastic cap from the top of the fuel pump floater assembly.
Remove the fuel pump floater assembly without spilling fuel…
Here they are side by side – place them side by side to make sure you get the sock orientation in the right way and also verify your wiring against the Walbro instructions provided. Make sure that if you are soldering the wires, that there is no fuel ANYWHERE where you are soldering and that you do this far away from the 240sx where you have the gas tank open.
I reused the stock sock as the one that walbro provided worked for honda prelude which has a different fuel tank design. If I were to use the one they provided, the pump would be starved from fuel more quickly. If your fuel sock is in bad condition / very dirty / clogged, it is very good idea to go dealership and buy a new one.