Fuel Q's - Walbro & Fuel pressure regulator

[DeeCee]

Hey hey,

Scenario: ST205 3SGTE into a ST185

stock ECU
stock fuel rail and injectors
stock turbo

I'm in the process of cleaning out the engine bay and removing seam sealer and such, but in a couple of weeks time I'll be looking at a new fuel pump when I start to re do all the lines in the car with copper nickel seamless piping.

ST205 has 540CC injectors (as you know), but I'm not looking at turbo upgrades or larger injectors as I've moved away of the idea of trying to pursue high kW out of the 3SGTE (for now lol) as that doesn't really interest me apart from having a solid performing car.

1. when I upgrade to a Walbro 255 lph fuel pump, do I need to upgrade the stock fuel pressure regulator or will the stock regulator work fine?

2. will the car run rich because of the upgraded fuel pump?

3. any other issues/things to think about?

I'd rather put money to other areas if possible and in the future if I move to a larger turbo, ecu etc, then I would look at a FPR

as always, mucho appreciado for any input

Dave

[postfach]

I put a Walbro 255L/h pump into my mates stock Caldina GT-T and it works exactly as the factory pump did, only noticeable difference is the noise it makes.

You don't need to worry about it running rich or anything like that, the factory regulator will work fine, any excess fuel will simply be returned to the tank.

[DeeCee]

noise won't be an issue. car will be extensively sound deadened lol

thats what I thought on the fuel return - cheers for confirmation

[postfach]

The walbro is nowhere near as loud as my bosch. I'm sure you won't notice it if you've got sound deadening installed.

[Dell'Orto]

I have to ask, why bother if you're not going to change the fuel requirements of the car? Or did you not get a 205 fuel pump?

[DeeCee]

It was only the engine, loom, ecu and accessories that I got, not the full car.

Well my old fuel pump is there and its fine, but it is 18 years old and its a different engine, so why not upgrade the pump, filter etc all at the same time

I will be hopefully increasing the boost and my aim is 200kw or close enough on the stock turbo etc with breathing mods and FMIC

[evil_si]

i have found on a few cars now that the walbro flows to much fuel for the stock reg to take care of, thus increasing fuel pressure and in most cases it runs rich and really boggy at take off

i recommend fitting an aftermarket reg to take care of this problem

[DeeCee]

Cheers for the info Simon

[levinguy]

i have found on a few cars now that the walbro flows to much fuel for the stock reg to take care of, thus increasing fuel pressure and in most cases it runs rich and really boggy at take off

i recommend fitting an aftermarket reg to take care of this problem

that is interesting, i think that might be the case with my car, standard sw20 3sgte with a 500hp warlbro pump, it doesnt go as well as i thought it would and its been using more fuel then i thought it would

do you think this could be the case for me?

[evil_si]

what i have noticed,

with a walbro and standrad reg, fuel pressure can be up around 52psi, this is far to much
depending on each setup it should be around 32-38psi at idle
if you have a rising rate fpr it will increase fuel pressure as it see's boost pressure and this is fine as the engine can take and burn it.

with to much fuel pressure at idle or off boost
problems can include bogging, back firing, sluggish to drive, fouling of plugs etc

[postfach]

We have not experienced this on the ST215W, guess it will vary between cars/motors.

[Adydas]

Food to munch on but you could chuck a nissan V6 fuel pump in tank as a stock replacment.. cost me peanuts second hand works fine with a warrenty from wrecker for a year.. And puts out enuf juice for the power my monster is making..

[levinguy]

just for the record my sw20 3sgte with walbro pump and standard reg has over 50psi of pressure in the rail at idle, looks like the standard reg can't keep up

[bluemaumau]

friends rb20 overfuels heaps, no reg but has a 500hp jobbie

[evil_si]

just for the record my sw20 3sgte with walbro pump and standard reg has over 50psi of pressure in the rail at idle, looks like the standard reg can't keep up

did that fitting work rob?

50psi is way to much, get a adjustable reg and drop it down to 34psi


there are bolt on kits to fit aftermarket regs available,
if you go this route make sure its going to seal reliably,
i much prefer removing the fuel rail and welding an adaptor to it and running jic fittings and pushlock hose to be on the safe side

[levinguy]

yup, perfect, thanks for that

will do, should go alot better

[mr30%jr]

little off topic are the 205 still using the dual speed pump?