Fuel Pressure Regulator PROBLEM!

[BOOSTJUNKIEGSX]

I have a AEM fuel rail, walbro 255lph, and 880cc injectors ect. I am having a major problem getting a stable fuel pressure and i have went through 2 brand new AFPR`s and neither of them work.


First i had a brand new aeromotive fpr and the gauge never worked at all, but the car ran.. took the vacuum line off and nothing changed..

Second i bought another fpr and the same exact thing occurred. The gauge didnt work but the car ran and the vacuum line made no difference on or off..

Third..I took the gauge and installed it right to my fuel rail and it finally reads, but it reads 50psi and no matter how much i adjust the FPR the psi is always at 50.....Also having the vacuum line on or off doesnt change a thing..

Any advice..

 

[BOOSTJUNKIEGSX]

Awesome...

 

[romeen]

It sounds like either the guage is defective or you did not install the FPR's correctly (no offense). The probability of having two successive FPR's be defective is very low. I doubt the accuracy of that 50 psi reading. If that was true you would be running so rich that the car would be running horribly. This leads me to think that it is most likely a defective guage.

 

[Raph]

I have a AEM fuel rail, walbro 255lph, and 880cc injectors ect. I am having a major problem getting a stable fuel pressure and i have went through 2 brand new AFPR`s and neither of them work.


First i had a brand new aeromotive fpr and the gauge never worked at all, but the car ran.. took the vacuum line off and nothing changed..

Second i bought another fpr and the same exact thing occurred. The gauge didnt work but the car ran and the vacuum line made no difference on or off..

Third..I took the gauge and installed it right to my fuel rail and it finally reads, but it reads 50psi and no matter how much i adjust the FPR the psi is always at 50.....Also having the vacuum line on or off doesnt change a thing..

Any advice..

a buddy had the excate sane problem..we treid my guage..no change..still read 50 psi (aeromotive) i have the same fpr and dont have this problem.

I wonder if its the guage catching on the spring in the fpr?or because of his fuel lines? i dunno if he ever figured it out.ill ask him

 

[BOOSTJUNKIEGSX]

I have used 2 different brand new gauges and two brand new FPR`s.. I have never had a problem like this.. They both read 50psi on the rail but read nothing on the unit itself, also the vacuum line chances nothing! Could it possibly be the return line? I replaced the fuel filter with a oem one when i was in there...

The car runs okay, but is dumping way to much fuel! and theres no way to adjust!

if i have the FP screw maxed in is that lower or higher..?

 

[Gary 420A RS]

When you tighten the screw it will go down. Turn the car on and take the nut off the fpr. Turn the screw with the allen head to adjust it where it needs to be.

 

[romeen]

I have used 2 different brand new gauges and two brand new FPR`s.. I have never had a problem like this.. They both read 50psi on the rail but read nothing on the unit itself, also the vacuum line chances nothing! Could it possibly be the return line? I replaced the fuel filter with a oem one when i was in there...

The car runs okay, but is dumping way to much fuel! and theres no way to adjust!

if i have the FP screw maxed in is that lower or higher..?

1) Yes, a kink in the return line can cause increased FP. You should examine it. There is about 1 foot of flexible line in the engine compartment and then it is hard line back to the tank.

2) Turning the adjustment screw clockwise/in should raise FP.

 

[BOOSTJUNKIEGSX]

Thanks guys.. I examined the fuel filter and return line. everything is good. when replacing the fuel filter i marked on the top screw the hole openings so i know its dead on and flowing correct.... Im going to buy a labtop and hopefully i can figure things out with dsmlink...

I have the fpr screw all the way in, so im going to back it out and see if it helps, because it changes nothing on the gauge....

 

[romeen]

With a banjo bolt the orientation of the holes shouldn't significantly affect fluid flow. It's more important to torque to specs to avoid a potential leak, especially since you're dealing with fuel.

This may sound silly but are you sure you are using the correct port for the fuel return (typically the bottom port on the FPR)? Do you feel tension against the adjusting screw when you turn it in? Are you sure that you are using the correct tension spring?

 

[GVR4592]

Post a picture of how you have the regulator installed and where the vacuum line is connected.

 

[BOOSTJUNKIEGSX]

Hope this helps.I have the aeromotive one also in my shed that was on with the same exact problems both new out of the box set up the same way as below!! I didnt realize you had to change out the springs?..But besides that nothing adjusts at all so i dont see that being the problem because it would atleast adjust something. It seems when i back out the fpr screw the idle goes down, but the gauges always read between 50-60... It just makes me curious why this is and what is going on...

 

[romeen]

I am not familiar with that AFPR but I think you might have the fuel "in" and "out" lines reversed. All of the regulators that I have seen have the fuel return line connected to the bottom port of the fpr (opposite of the way it is showing in the picture).

Also I can't tell where the vacuum line is. I don't see one connected to the fpr at all.

Are you sure that the fpr is a boost referenced fpr that raises at a 1:1 ratio with manifold pressure? If you have an Aeromotive unit I would recommend using that one. Which model number is it?

Also make sure that you are using high quality fuel hose and fuel clamps. I'm not trying to be overly critical but you don't want to take any chances with your fuel system....the last place you want to leak.

Let us know which Aeromotive unit you have and we can help you set it up.

 

[toyotaturbo]

I am not familiar with that AFPR but I think you might have the fuel "in" and "out" lines reversed. All of the regulators that I have seen have the fuel return line connected to the bottom port of the fpr (opposite of the way it is showing in the picture).

Also I can't tell where the vacuum line is. I don't see one connected to the fpr at all.

Are you sure that the fpr is a boost referenced fpr that raises at a 1:1 ratio with manifold pressure? If you have an Aeromotive unit I would recommend using that one. Which model number is it?

Also make sure that you are using high quality fuel hose and fuel clamps. I'm not trying to be overly critical but you don't want to take any chances with your fuel system....the last place you want to leak.

Let us know which Aeromotive unit you have and we can help you set it up.

I agree with you.....those lines look reversed. Switch them around and see what happens.