can i use walbro 255 with stock, injectors, ecu/motor

You can install the fuel pump without upgrading anything else. The fuel pressure regulator is what determines the fuel pressure, not the pump, so a stock regulator will the keep the pressure the same regardless of what pump you run.

The higher output pump comes into play when you run bigger injectors, and require a higher volume of fuel to be pumped to keep up with them.

the base fuel pressure can vary slightly when using a different/more powerful pump than what's currently on the car. You should always adjust if you have the capability to. Going from a the stock z31 to the kyosan denso 1020 i put in, I had to readjust my pressure by something like 2 psi (kinda hard to tell, but noticeable on the gauge). It's really not a big deal anyways- but I have the capability to adjust it so why not, right? with a walbro 255 it should be a very minimal increase if it does go up, so in this case it should be fine.


putting in a newer higher flowing pump is something a lot of people do when replacing the stocker as a precursor to future upgrades while still using stock stuff, and it's been fine for them. Technically, I did the same thing as well, and it seemed to operate just fine.

I have a Walboro 255 in my current vg33 setup with stock computer/injectors with no issues. Mainly because my Nistune is having troubles so i went back to stock for now. I also have the ability to adjust fuel pressure though

Awesome thanks guys. Might as well install it now and get it over with

I heard with the higher pressure fuel pumps it is a good idea to do the constant 12v mod for the fuel pump.

Also from my install experience, check your connections. I had a fuel pump connector fail after a few years of running the walbro.
http://z31performance.com/showthread…onnector-baked

its a good idea for any fuel pump.

I have read that thread end to end and I don't think I ever saw actual agreement on how to do this lol. That's gotta be the worst sticky thread on the board. The most sensible instructions seemed to me to be these ones:

"Easiest way is to put a relay in the rear of the car. Run OE fuel pump + to Relay PIN 85, and OE fuel pump - to Relay PIN 86. Run new power wire from battery (fused up near the battery) to the relay PIN 30, and then relay PIN 87 to the fuel pump +. Run the fuel pump - to a bolt on the body. It'll be full voltage for the first 5 seconds of key on, and whenever the engine is running, just like the OE ECU controls it other than being full voltage 100% of the time"

with the minor PITA of running the power wire if you haven't relocated the battery. Thoughts anyone?

I spliced the relay into the fuel pump positive feed. I had no intention of running a wire from the battery, as long as it's not blowing the fuse there is no problem IMO. All in preparation for a Bosch 040.

pretty sure i just took the main power going to the pump- cut it, and wired the harness side into one side of the relay coil, and then grounded the other side of the relay coil. then ran a 10gauge wire from the front to the relay, and then to the pump by removing the length of the original power wire that was left on the pump after cutting it and using it for the relay coil.

seems to work.

i also took a water proof fuse holder, took the cap, drilled a 1/8th hole in it, and dripped some thick clear drying epoxy into the inside of the cap to create a visible bulb in the cap. then i put the fuse holder near the speed sensor for the digital dash, and i put a ATO lite-fuse so that if it blows, it glows! (through the cap). So if ever the car stops running, that would be the first thing I check.

This was the reference site I used and I successfully did the mod
http://www.tboz31.com/300ZX/FuelPump…PumpRelay.html