Fuel Pressure Regulator

[Shoryuken]

I was going to put a walbro intank fuel pump in my R33 GTR today but my friend told me that I need to get an aftermaket fuel pressure regulator first or else the car will run lean and use more fuel, is this true?

[T.D]

Get a new mate. Seriously.

When a car runs lean, it means more air, less fuel. What he said to you contradicts itself.

If I'm not mistaken (and hopefully someone can correct me if I'm wrong), the fuel pump will deliver x amount of fuel and your engine will consume y amount of fuel. Anything that doesn't get consumed, is returned back to the tank.

The car will run rich if you drop in larger injectors (provided it runs well enough at all) without a tune. In that case, it will consume more fuel than required.

Long story short, an adjustable fuel pressure reg isn't required if you're running the right size injectors and fuel pump.

Edited April 3, 2013 by turbodragon

[Shoryuken]

So the walbro pump should be fine with standard 440cc injectors?

[scotty nm35]

Yes, but it will need to be hardwired through a relay.

What type of Walbro are you putting in? I hope it's a 400L as the stock GTR pump outflows the 255L's.

[Shoryuken]

wtf? It's the 255l one...

[ARTZ]

Get a new mate. Seriously.

LOL!

[GTSBoy]

There is one aspect of putting a big pump in that can make the engnie run rich. If it was previously tuned with a pump that was not able to keep up, such that rail pressure was dropping at high loads then the bigger pump will maintain higher rail pressure and the same injector duty cycle will dump in more fuel. Could be a little extra, could be a lot, depending on how bad the situation was before.

[Shoryuken]

What type of Walbro are you putting in? I hope it's a 400L as the stock GTR pump outflows the 255L's.

Surely a new 255L walbro would flow more then a 18 year old GTR pump?

[XRATED]

Don't let your 'mate' anywhere near your car.... matter of fact, you shouldn't touch it either. seek professional help.

J.