new nismo fpr and new gauge. gauge reading pass max?

[dvd]

ok i shoudl make a new thread. Basiclly I got a new nismo fpr and a new mechanical pressure gauge installed. I have my fuel pump set to a switch. So this is basicly what happened.

1. turn pump on2. examine the gauge3. gauge is reading way pass the max 60psi4. loosen the adjustment nut all the way off5. gauge reads a little lower but still doesnt even reach the max 60

if i tighten the nut halfway, there would be squealing noises. Also with the adjustment nut all the way out the gauge would read around 10psi with the pump off.

faulty fpr? faulty gauge?

[biosehnsucht]

Fuel line from tank - fuel filter - gauge - fuel rail - fpr - return line to tank.

Is this how you have these hooked up?

Are you using a stock pump or something else? My NISMO fpr regulates my Walbro 255lph (high pressure model) just fine..

[dvd]

Fuel line from tank - fuel filter - gauge - fuel rail - fpr - return line to tank.

Is this how you have these hooked up?

Are you using a stock pump or something else? My NISMO fpr regulates my Walbro 255lph (high pressure model) just fine..

i have a high pressure inline walbo. this is for my datsun 510 so basicly its

tank --> 300zx filter ---> walbro pump ---> 300zx filter --->pressure gauge -->fuel rail --->fpr ---> tank.

The 2nd filter is a new filter.

[Bwana]

I'd try a new gauge first.

[dvd]

yaeh i'll probalby do that since its the easiest. I hope kragen will let me return it if it isnt the gauge.

any other ideas guys?

[float_6969]

Are you sure you don't have an obstruction for the line going back to the tank? Could it be plugged up or kinked?

[dvd]

going back to the tank is just a hardline and another softline that goes into the tank.

[biosehnsucht]

maybe try bypassing the fpr (so no regulation, pressure should be as low as possible with whatever restriction the piping gives) and see if you get sane (i.e. low) readings from the gauge.

Where does the squealing come from? if its the gauge, then I'd think its bad. If its from someplace else, then maybe clog..

[float_6969]

i have a high pressure inline walbo. this is for my datsun 510 so basicly its

tank --> 300zx filter ---> walbro pump ---> 300zx filter --->pressure gauge -->fuel rail --->fpr ---> tank.

The 2nd filter is a new filter.

Try this. You'll just need some extra fuel line.tank->filter->pump->filter->gauge->tank

That should narrow the problem down to the return line or the gauge. You should have little to no pressure with that setup.

Try that and let us know what happens.

[dvd]

well i unhooked the gauge and the needle was stuck on 12psi. So i'm leaning very close to a broken gauge. In the beginning I messed up by doing this.

fuel pump --> filter -->gauge --> fpr RETURN could that have messed up the gauge?

[dvd]

ok i changed the gauge and it still reads to 60 now. Any other suggestions? I think i'm just going to try to put the stock one back.

[float_6969]

Wait, are you saying that you hooked up the fuel lines backwards? If you fed pressure into the wrong side of the FPR, it MIGHT have damaged it. Unlikely though.

If you're reading 12psi with the gauge unhooked, it's definetly bad.

It might be possible that you got a faulty FPR.

Check your pressure again if you put the old one back on.

Maybe you can get a refund.

[dvd]

yeah hopefully i can get a refund. The new gauge i have now works fine. Going to put the old fpr back. damn those philip screws that hold the fpr in place.

[float_6969]

1/4" drive socket wrench plus a phillips bit FTW!

[dvd]

hey for those using a walbro, are your hoses pretty stifff when the pump is on? or car?

anyways I installed the stock one back and the gauge would still go up when the pump is on. But when you turn it off the gauge would show 36psi(isnt that stock pressure?). with the car on the gauge still shows past 60, so i'm wondering if i'm boosting, will i blow the gauge up if it were to try to go past the max the needle can go?

[biosehnsucht]

Definately get some small hex cap screws to replace them phillips.. :P I nearly destroyed mine to the point of being unable to remove the stock FPR.

well, to go past 60 you'd have to be doing more than 24 psi of boost..

It may be you can't return enough fuel somehow, with the amount the walbro is sending. When car off, no pumping, fpr is able to let down to 36. Mine drops well below 36 when the car's off.

My stock CA fpr was horribly overrun by the 255lph high pressure walbro, which is why I got the nismo fpr, which works fine for me..

[dvd]

oh so i verified some things. so when u turn the pump on then turn it off again. THATS when it supose to read 36 or so right? Not while the pump is on?

[float_6969]

NO. With the motor not running, just the fuel pump running, it should read 36 psi. If everything is working properly when you turn the pump off the pressure should stay up for quite some time before it bleeds down. I've had mine still holding 3-7psi after sitting all night.

I'm quite confident that you don't have 2 bad FPR's.

The ONLY thing that can cause the symptoms that you're experiencing is a restriction in the return line going back to the tank.

Double check your rubber lines for kinks and all of the hard lines for collapse or bends.

Something isn't letting the fuel go back to the tank like it should and is falsely increasing the fuel pressure.