Hey Red!
I just wanted to know if you upgraded your return fuel line when you installed your Walboro 2551ph HIGH PRESSURE MR2 Fuel pump.The reason why im saying this is because i have the exact same Fuel pump and im getting Extremely high Fuel pressure readings at idle.
Bacically whats happening is my car reads 60psi at idle and i have always had it set to 44psi at idle.I turned down the FPR to the lowest and it only hit 58psi so i then drove the car around for about 30 minutes then when i stopped i noticed my fuel pressure was up to 62psi at idle.I also pulled off the vacum line and it was reading 6psi higher.
My machanic told me taht the return line needs to be enlarged.
He also told me to let the car rev at 3000-3500RPMS and see what the Fuel pressure gauge reads and this way you can determine what my Fuel pressure is at?
Here is the link from Hyundai perdormance forum?
Any help would be appreciated!
http://www.hyundaiperformance.com/forums/t...pic.php?t=13469

 

Nope, didn't upgrade it. In fact, I'm still using the stock regulator and my fuel pressure is pretty crazy at idle. But I never really cared, because the Haltech isn't having any problems getting injectors ramped down tight enough to idle correctly.

I'm really not convinced the return line is too small... Have you removed the stock fuel regulator from the injector rail?

 

Red!
My stock regulator was removed when i had to install the regulator from Alpine,then it went on me last couple of months ago and purchased an AEM universal FPR 1:1 ratio!

 

Ok, time to tell me exactly what parts you have that deal with the fuel directly.

You should have:

Fuel pump
Fuel line
Fuel filter
Fuel rail
Fuel injectors
Fuel pressure regulator (adj. static)
Fuel pressure regulator (adj. rising rate)
Fuel return line

Is the list above correct?

 

Jason i have the Walboro 2551ph High pressure fuel pump
Stock fuel filter
440cc RC injectors
AEM 1:1 ratio FPR
Stock feed and return fuel lines!

Also i preformed a few tests today which was first of all to rev the car at 3500rpms and see what the gauge is reading.Im currently running 64psi at idle.I reved the car at 3500rpms and it still reads 64psi
A friend of mine has the same AEM FPR 1:1 ratio as i do and he told me to change the ORFUS inside the FPR to a larger one which comes with the kit when you purchase it.The stock one inside the FPR is the smallest from factory which is installed!!
You think this can also fix the problem if i was to change the ORFUS!

 

Orfice is the word...

The AEM is there only to adjust fuel pressure while you're boosting (the numbers 1:1 refer to 1psi more fuel pressure per 1psi pound of boost)

There needs to be TWO fuel pressure regulators -- the one you've got, and a static pressure regulator to determine the fuel pressure during all the time you're not on boost (like at idle)

Are you really sure the stock static regulator isn't still installed on the end of the fuel rail? 65psi is what I'm running on my fuel rail all over the place, and that's because the stock regulator is still installed along with that 255lph pump. The problem is that the stock regulator just cannot flow enough to return all that fuel back to the tank...

 

RED!
The funny thing is i have always had my car idle at 44psi until last week when i noticed it up to 64psi at idle!

Im 100% sure the stock regulator was ripped out to install the Alpine FPR before it went on me and had to purchase the AEM FPR

What kind of static FPR do you recommend?
How much are they!
After the tests i preformed do you think the return line can still be the problem and needs to be enlarged?
Thanks !

 

You don't have to rip out the stock regulator in order to install an aftermarket rising rate unit.

The question is: what changed? You said it used to idle at 44psi until a week ago. What has changed?

If nothing has changed that you know of, then it's time to start troubleshooting your fuel system.