Jump to content
SAU Community

Recommended Posts

Has anyone ever had problems with the Walbro 255lph fuel pump. I have a pretty stock R32 GTR and was running fine and pulled well through boost with low knock. I decided to put a Walbro GSS342 255lph on cause my stock pump seemed to be given up from setting around. With the Walbro my knock goes through the roof if I try to make a pull. I ran a 12v to the back on a relay cause I thought it might not be getting enough juice. The car ran great last I drove it about 6 months ago. I have had the car in a storage container waiting on a new radiator. The pump was bought from amazon so was thinking I might have got a knock off.  Do fuel pressure regulators go bad? Should I just buy a Tomei pump or look for other issues.

Link to comment
https://www.sau.com.au/forums/topic/483466-bad-walbro-255-or-something-else/
Share on other sites

That is what happened to my stock pump. The walbro was new and not used, but I have had it about a year waiting til my stock one kicked the bucket. Surely it would not go bad from not being used if it had never been used. 

On 19/03/2022 at 11:34 AM, Dustin Frazee said:

That is what happened to my stock pump. The walbro was new and not used, but I have had it about a year waiting til my stock one kicked the bucket. Surely it would not go bad from not being used if it had never been used. 

Definitely unlikely for an unused fuel pump to be bad, but anything is possible. Go change your fuel filter first.

I had some weird hesitation issues after installing my Walbro 255, I have been meaning to try it with a 12v supply but just haven't gotten around to it. I've since returned it to the stock pump as the pump wasn't the cause of my issues in the first place anyway. 

I'm interested to know how your situation goes.

On 19/03/2022 at 1:59 PM, Dustin Frazee said:

Yeah I put some new fuel in and still the same. Should I be running the little regulator thing with the new pump? I am not sure if it is a check valve or what.

Screenshot_20220318-232655_Google.jpg

Fuel pressure relief valve, get rid of it as it can cause more dramas than retaining it, as the opening pressure is fairly low from memory. If it fails or activates, it just pumps the fuel out into the tank and you get no fuel to your engine.

This may be your problem if it has stuck open or partially open.

So if your car is actually running, what is your actual fuel pressure at idle and on load ? Really gotta go back to basics here and make sure you have an unblocked fuel filter then confirm your actual fuel pressures before guessing about anything.

On 19/03/2022 at 3:29 PM, Dustin Frazee said:

Yeah I put some new fuel in and still the same. Should I be running the little regulator thing with the new pump? I am not sure if it is a check valve or what.

Screenshot_20220318-232655_Google.jpg

Remove it asap!

Every S15 I tuned with lean out issues turned out to be running the OEM pressure relief valve in the tank, as soon as you hit about 1 bar or so of boost you see AFRs lean to the moon.

Deleted it and had to redo the entire fuel map.

On 23/03/2022 at 10:24 AM, joshuaho96 said:

Don't fuel pumps already have pressure relief valves?

External pumps no. Intank pumps like the Walbro or AEM pumps yes, but generally the ones that are internal to the pump on these are usually rated to something around 120psi. This is definitely an area that is compromised on knock off pumps too.

That Nissan heap of shit is something as low as 75psi. Now imagine 40+psi base pressure, 15psi boost plus fuel line losses of 15psi upwards with shitty 5/16" lines and you are already getting scary close to it opening - IF it is working correctly.

  • Like 2

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


  • Similar Content

  • Latest Posts

    • Place the new daughterboard in the case and mount it using the 3 small black rivets provided, and reconnect the 3 factory ribbon cables to the new board Then, use the 3 piggyback cables from the daughterboard into the factory board on top (there are stand offs in the case to keep them apart. and remember to reconnect the antenna and rear cover fan wires. 1 screw to hold the motherboard in place. Before closing the case, make a hole in the sticker covering a hole in the case and run the cable for the android unit into the plug there. The video forgot this step, so did I, so will you probably. Then redo the 4 screws on back, 2 each top and bottom, 3 each side and put the 2 brackets back on.....all ready to go and not that tricky really.      
    • Onto the android unit. You need to remove the top screen because there is a daughterboard to put inside the case. Each side vent pops out from clips; start at the bottom and carefully remove upwards (use a trim remover tool to avoid breaking anything). Then the lower screen and controls come out, 4 screws, a couple of clips (including 3 flimsy ones at the top) and 3 plugs on the rear. Then the upper screen, 4 screws and a bunch of plugs and she is out. From there, remove the mounting brackets (2 screws each), 4 screws on the rear, 2 screws top and bottom and 3 screws holding in the small plates on each side. When you remove the back cover (tight fit), watch out for the power cable for the fan, I removed it so I could put the back aside. The mainboard is held in by 1 screw in the middle, 1 aerial at the top and 3 ribbon cables. If you've ever done any laptop stuff the ribbon cables are OK to work with, just pop up the retainer and they slide out. If you are not familiar just grab a 12 year old from an iphone factory, they will know how it works The case should now look like this:
    • Switching the console was tricky. First there were 6 screws to remove, and also the little adapter loom and its screws had to come out. Also don't forget to remove the 2 screws holding the central locking receiver. Then there are 4 clips on either side....these were very tight in this case and needed careful persuading with a long flat screw driver....some force required but not enough to break them...this was probably the fiddliest part of the whole job. In my case I needed both the wiring loom and the central locking receiver module to swap across to the new one. That was it for the console, so "assembly is the reverse of disassembly"
    • But first....while I was there, I also swapped across the centre console box for the other style where the AV inputs don't intrude into the (very limited !) space.  Part# was 96926-4GA0A, 284H3-4GA0B, 284H3-4GA0A. (I've already swapped the top 12v socket for a USB bulkhead in this pic, it fit the hole without modification:) Comparison of the 2: Basically to do the console you need to remove the DS and PS side console trim (they slide up and back, held in by clips only) Then remove the back half of the console top trim with the cupholders, pops up, all clips again but be careful at the front as it is pretty flimsy. Then slide the shifter boot down, remove the spring clip, loose it forever somewhere in the car the pull the shift knob off. Remove the tiny plastic piece on DS near "P" and use something thin and long (most screwdrivers won't fit) to push down the interlock and put the shifter down in D for space. There is one screw at the front, then the shifter surround and ashtray lift up. There are 3 or 4 plugs underneath and it is off. Next is the rear cover of the centre console; you need to open the console lid, pop off the trim covering the lid hinge and undo the 2rd screw from the driver's side (the rest all need to come out later so you can do them all now and remove the lid) Then the rear cover unclips (6 clips), start at the top with a trim tool pulling backwards. Once it is off there are 2 screws facing rearwards to remove (need a short phillips for these) and you are done with the rear of the console. There are 4 plugs at the A/V box to unclip Then there are 2 screws at the front of the console, and 2 clips (pull up and back) and the console will come out.
    • So, a bit of a side trip, but one that might be interesting for people with JDM cars and japanese head units. I know @Pac previously posted about a carplay/android auto adapter he installed which used the AUX input, and @V35_Paul put in one of the Tesla style units that replace both screens. The option I went with was a Lsait LLT-YF-VER5.87_2 (https://www.alibaba.com/product-detail/Lsailt-8GB-Android-Multimedia-Interface-for_1601187633672.html). Price was $1,150 for a single unit although they are much cheaper if you are willing to buy 2....$857ea. Make you you get the version 2 not version 1, it is faster and has a better UI - this is the manufacturer listing: http://www.lsailt.com/product/348.html. BTW if you've never bought from Alibaba before, don't be concerned....these guys can't stay in business unless they are responsive, ship fast etc, they were excellent (probably faster shipping than most local places) So, this was my task for a lazy Sat afternoon....looks complex but was all done in a few hours (it probably helps that I had some of it apart before so it was a bit familiar). I also decided to add a HD USB drive recorded at the same time and the unit also supports an aftermarket reverse cam (if you don't want to retain factory) and also AV in and HDMI out It looks much worse than it is, in fact in was genuinely all plug and play (no custom wiring at all). This video was pretty good (skipped a few steps), unfortunately they are an Aussie seller but no longer sell this unit (I guess Carplay/AA adapters are easier to install and much cheaper) https://www.youtube.com/watch?v=T5hJfYOB8Dg
×
×
  • Create New...