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Fuel regulator "pulsing"

SkylineCR
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SkylineCR Newbie

SkylineCR

Posted
Posted

Hi guys, hope I wish you could help me. 

Change fuel regulator, fuel pump, dynamics injectors 1050cc, fuel rail (radium) on my skyline R33. It keeps staying lean when warms up. Fuel regulator have kind of pulse and it is undriveable. I'm going to clean my fuel tank and lines, but just trying to find out what could be. 

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Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted

Do you have all hard lines or stainless braided lines to and from the rail, etc.?

if so you might have fuel pulsation issues. I had the same on my car and another car I setup running a big fuel system and fairly hard lines. A way to stop this from happening is to install a Fuel Pulsation Damper (FPD), Radium have a few decent ones:

20-0199.jpg?20220524141523

20-0177.jpg?20220524131317

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robbo_rb180 Grand Master

robbo_rb180

Posted
Posted
1 hour ago, SkylineCR said:

Hi guys, hope I wish you could help me. 

Change fuel regulator, fuel pump, dynamics injectors 1050cc, fuel rail (radium) on my skyline R33. It keeps staying lean when warms up. Fuel regulator have kind of pulse and it is undriveable. I'm going to clean my fuel tank and lines, but just trying to find out what could be. 

How is the fuel pump wired?

Has the ecu been setup after all these changes? Got a wideband on it?

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GTSBoy Grand Master

GTSBoy

Posted
Posted

Not only is it pulsating, but the centre of the range of the pressure appears to be about half what it should be. Why is the reg not wound in to give ~43 psi base pressure. That could be all of your lean issue right there.

And, I second the following

21 minutes ago, robbo_rb180 said:

How is the fuel pump wired?

Has the ecu been setup after all these changes? Got a wideband on it?

Why did you change these parts, and is the rest of the package able to handle it? What size were the previous injectors?

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Murray_Calavera Mentor

Murray_Calavera

Posted
Posted
4 hours ago, SkylineCR said:

Thanks guys, for your quick response. I'm going to buy that fuel damper. Started to fail after changing injectors and fuel rail. We tuned my car again and keep doing the same. Wideband shows AR sooo lean. 

I've got a very similar setup to you (radium rail, 1050's, etc). Just a heads up, the shorter fuel pulse damper fits in the rail. 

http://www.radiumauto.com/Assets/ProductImages/20-0776_FPD.jpg

I used 2 of them in my rail, you can kinda see them if you squint. 

 

 

20220929_135637.jpg

  • Like 1
Murray_Calavera Mentor

Murray_Calavera

Posted
Posted
9 hours ago, Dose Pipe Sutututu said:

Nice Radium fuel filter too @Murray_Calavera 😎

It's one of these bad boys :)

http://injectordynamics.com/id-f750-fuel-filter/

It can measure the fuel pressure drop across the filter so you know exactly when to change it - so fkn sexy!

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Neostead2000 Enthusiast

Neostead2000

Posted
Posted

What about the pre-existing fuel dampers which Nissan put, all 3 of 'em? At least on my neo there are 3, one right after the fuel pump inside the tank, one mounted on the strut tower and one on the inlet side of the fuel rail.

Having rubber lines actually helps with pulsation dampening, but it is true that bigger injectors like to "pound" harder inside the line especially at certain resonances. Also I've had that same AFPR gauge behavior on my other car (which has 1000cc jets and NO fuel dampers) and it was an improperly set pressure (way too high) which caused the spring to get mega stiff and was bouncing up and down inside. P.S if your gauge has a little valve on the side, make sure to "pop" it once to reset and recalibrate it to your ambient pressure right now. Liquid filled gauges love to read off by tons if they have never been recalibrated and ambient pressures have changed.

Murray_Calavera Mentor

Murray_Calavera

Posted
Posted
1 minute ago, Neostead2000 said:

What about the pre-existing fuel dampers which Nissan put, all 3 of 'em?

I can only speak for myself, but they are in the bin! 

The radium setup with them in the rail is much tidier then having external dampers. 

  • Like 1
Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted
41 minutes ago, Neostead2000 said:

fuel pump inside the tank

into the bin, (not sure for R34s but in S15 it's actually a pressure relief valve and as soon as you add boost it cracks open and your fuel pressure turns to shit).

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