Jump to content
SAU Community

Sard Adjustable Fpr Not Going Higher Than 22Psi

R32 25 Slider
 Share

Recommended Posts

R32 25 Slider Newbie

R32 25 Slider

Posted
Posted

I just upgraded my injectors to 550cc yellow tops out of a subaru.

Since that my Sard FPR guage only reads 22psi. I tried adjusting it and it can go lower than 22 psi but it wont adjust to make higher than 22 psi. The needle shakes at the highest 22 psi figure I can get.

When i turn the key and the fuel pump pumps the fpr guage shows 40 psi then once the car is turned over it goes down to 22PSI, why is this?

My question is, any ideas why this would be happening? (is the FPR faulty?)

Is it safe to drive at 22 PSI? or will it lean out?

To give a background on my fuel system upgrade that also might be linking to it. I replaced the faulty walbro pump it had with a new one and the FPR went up from 40 psi to 50 psi and then just yesterday I replaced the fuel rubber lines from the boot as one had a tiny cut and was leaking and thats when i also replaced the injectors, since then only getting 22PSI on the FPR guage

JonnoHR31 Grand Master

JonnoHR31

Posted
Posted

remove the vac line and see what your base pressure is. then if it wont go any higher than ~45psi try slowly crimping the return line after the reg with some pliers (carefully!), keeping an eye on the pressure, and see if it goes up. if it does the reg is f**ked, if it doesnt your pumps f**ked

R32 25 Slider Newbie

R32 25 Slider

Posted
  • Author
Posted

ok, so i've just done what you said to do and the guage psi value didnt move. so this would mean the fpr is fine and that my fuel pump is f**ked...

but the fuel pump is a brand new genuine walbro one that just got installed 2 weeks ago. The reason i replaced the fuel pump was because the walbro that was in there would start making loud surging noises at random moments and would keep getting louder until you turned the engine off, also the fpr guage would go nuts surging between 20 to 50 psi etc.

so if it really is the fuel pump, what keeps killing them?

BOOZTJUNKEY Proficient

BOOZTJUNKEY

Posted
Posted (edited)

Dodgy wiring or relay ? Possibly have constant power going to the pump u could put a multi Meter on the pump with the power off to make sure it's turning of with when the power is off

Also check what voltag u get at the pump with th power on if it's on factory wiring it will be around 10 or 11 volts any less and there could be a wiring issue

Is it wired directly to the battery or just factory wiring ? I would get the pump rewired to battery if it's factory still there is a write up in DIY section

Are u sure u put enough pressure on the line when u squezed it ?

Edited by BOOZTJUNKEY
R32 25 Slider Newbie

R32 25 Slider

Posted
  • Author
Posted

re squeezed it to make sure and i was putting as much pressure on it as i could, the needle is just fluttering around 22 psi so i wouldnt have expected it to rise anyway as it cant seem to get past that point. thinking of just getting another fpr to atleast rule that out or in hope it will fix.

check the power to fuel pump ans its only going when car is ON and its not a direct line but gets about 11.5V

scotty nm35 Grand Master

scotty nm35

Posted
Posted

+1^^^ Walbro pumps don't like the low voltage the stock fuel pump sees at idle. If it hasn't been done rewire the pump power using a relay as described in the many threads on the subject.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Duncan
      Mistakes were made, my R34 Story

      By Duncan · Posted

      Have a look at that (shitty) pic I posted. You can see AN -4 braided line coming to a -4 to 1/8 BSPT adapter, into a 1/8 BSPT T piece. The Haltech pressure sender is screwed into the long arm of the sender and factory sender (pre your pic) into the T side. You can also see the cable tie holding the whole contraption in place. Is it better than mounting the sender direct to your engine fitting......yes because it removes that vibration as the engine revs out 50 times every lap and that factory sender is pretty big. Is it necessary for you......well I've got no idea, I just don't like something important failing twice so over-engineer it to the moon!
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      Yup. You can get creative and make a sort of "bracket" with cable ties. Put 2 around the sender with a third passing underneath them strapped down against the sender. Then that third one is able to be passed through some hole at right angles to the orientation of the sender. Or some variation on the theme. Yes.... ummm, with caveats? I mean, the sender is BSP and you would likely have AN stuff on the hose, so yes, there would be the adapter you mention. But the block end will either be 1/8 NPT if that thread is still OK in there, or you can drill and tap it out to 1/4 BSP or NPT and use appropriate adapter there. As it stands, your mention of 1/8 BSPT male seems... wrong for the 1/8 NPT female it has to go into. The hose will be better, because even with the bush, the mass of the sender will be "hanging" off a hard threaded connection and will add some stress/strain to that. It might fail in the future. The hose eliminates almost all such risk - but adds in several more threaded connections to leak from! It really should be tapered, but it looks very long in that photo with no taper visible. If you have it in hand you should be able to see if it tapered or not. There technically is no possibility of a mechanical seal with a parallel male in a parallel female, so it is hard to believe that it is parallel male, but weirder things have happened. Maybe it's meant to seat on some surface when screwed in on the original installation? Anyway, at that thread size, parallel in parallel, with tape and goop, will seal just fine.
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      How do you propose I cable tie this: To something securely? Is it really just a case of finding a couple of holes and ziptying it there so it never goes flying or starts dangling around, more or less? Then run a 1/8 BSP Female to [hose adapter of choice?/AN?] and then the opposing fitting at the bush-into-oil-block end? being the hose-into-realistically likely a 1/8 BSPT male) Is this going to provide any real benefit over using a stainless/steel 1/4 to 1/8 BSPT reducing bush? I am making the assumption the OEM sender is BSPT not BSPP/BSP
    • funkymonkey
      Jacks that fit under GTR lips that can reach the subframe?

      By funkymonkey · Posted

      I fashioned a ramp out of a couple of pieces of 140x35 lumber, to get the bumper up slightly, and then one of these is what I use
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      I wouldn't worry about dissimilar metal corrosion, should you just buy/make a steel replacement. There will be thread tape and sealant compound between the metals. The few little spots where they touch each other will be deep inside the joint, unable to get wet. And the alloy block is much much larger than a small steel fitting, so there is plenty of "sacrificial" capacity there. Any bush you put in there will be dissimilar anyway. Either steel or brass. Maybe stainless. All of them are different to the other parts in the chain. But what I said above still applies.
×
×
  • Create New...