Fuel regulator "pulsing"

[SkylineCR]

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. 

[Dose Pipe Sutututu]

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:

[robbo_rb180]

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?

[SkylineCR]

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. 

[Dose Pipe Sutututu]

Yep that's fuel pulsation, try pull off your return line (post reg) and dump it into a jerry can. 

Does it go away?

[GTSBoy]

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?

[Murray_Calavera]

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. 

 

 

[Dose Pipe Sutututu]

Nice Radium fuel filter too @Murray_Calavera 😎

[Murray_Calavera]

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!

[Neostead2000]

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]

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. 

[Dose Pipe Sutututu]

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).