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Walbro 400Lph Problem

Hadouken

By Hadouken,
in Engines & Forced Induction

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MrStabby Grand Master

MrStabby

Posted
Posted

mine surged on 1/4 tank Lol

so you're pretty lucky to not surge on E

Agreed - mine also starts to surge at around a quarter tank. Sard pump with all the stock mounting stuff. Jez needs to corner faster :devil:

The sudden loss of all power is a give away - no wideband required.

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XKLABA
XKLABA

Don't flatter your self about the non return valve idea, we have been using them for more then 20years in the race cars My brothers car, I don't have a pic of mine in my phone It runs a VQ35HR wi

scotty nm35
scotty nm35

Because it is perfect, for me and my setup. I guess you just don't appreciate the hard work I put into it, designing a failsafe system on my own, using a single reg and return when everyone on here wa

Ben C34
Ben C34

To seperate the banks and use one reg wouldn't it go Pump > rail> non return > tee piece to common reg on both sides? Pretty easy.

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  • 2 weeks later...
Hadouken Grand Master

Hadouken

Posted
  • Author
Posted

So after a long day of testing today, they problem is as follows.

The pump has a main inlet where the hose and sock are connected, then there are 2 little holes where the fuel comes out. A priming/flow method for the pump.

Once the fuel level gets to below the fuel pump (where the 2 holes are exposed to air) the fuel pump needs 5 or 6 seconds of priming from a constant 12 volts before it starts to flow. In a GTR with a 0.7 sec priming cycle added to fuel rail pressure and the time it takes large injectors to fire = a long time of cranking over.

Now this is only a problem in applications where the fuel pump does not sit at the bottom of the tank i.e 33 34 GTR's. 32GTR's have a different fuel pick up set up hence no problem.

So seeing as I was the first 33GTR in unigroup to try the 400lph I was the lucky customer to be the guinea pig :S. boo I say.

Any way the solution Bosch 044 in tank haha.

Maybe nismoid can put this in his "handy threads" sticky to make it known for anyone who wants to run a 400lph Walbro, NOT to do so if the fuel pump is mounted in any other way other than close to the bottom.

Cheers

The dutch

GTScotT Grand Master

GTScotT

Posted
Posted

Surely if the priming time was the issue you could extend the prime time? Why not give it a constant 12v.

Well if youve already put the 044 then thats that I guess.

Wanna sell your 400LPH?

Hadouken Grand Master

Hadouken

Posted
  • Author
Posted

The priming time would have to be changed to 8sec. Now that can be avoided if I just go to a 044.

As I said, I was at Unigroup all of yesterday, and we were testing pumps left right and centre. Tested 3 walbro 400lph outside the tank, and tested a 044.

The 400l was fine when submerged but no good when exposed to air. Did I really want a priming cycle of 8sec or maybe even more every time? No.

So we rigged up a 044 and did a swap, my 400l for the Bosch.

In short, sorry mate don't have the pump.

  • 2 weeks later...
R33huntme Community Regular

R33huntme

Posted
Posted (edited)

So after a long day of testing today, they problem is as follows.

The pump has a main inlet where the hose and sock are connected, then there are 2 little holes where the fuel comes out. A priming/flow method for the pump.

Once the fuel level gets to below the fuel pump (where the 2 holes are exposed to air) the fuel pump needs 5 or 6 seconds of priming from a constant 12 volts before it starts to flow. In a GTR with a 0.7 sec priming cycle added to fuel rail pressure and the time it takes large injectors to fire = a long time of cranking over.

Now this is only a problem in applications where the fuel pump does not sit at the bottom of the tank i.e 33 34 GTR's. 32GTR's have a different fuel pick up set up hence no problem.

So seeing as I was the first 33GTR in unigroup to try the 400lph I was the lucky customer to be the guinea pig :S. boo I say.

Any way the solution Bosch 044 in tank haha.

Maybe nismoid can put this in his "handy threads" sticky to make it known for anyone who wants to run a 400lph Walbro, NOT to do so if the fuel pump is mounted in any other way other than close to the bottom.

Cheers

The dutch

so the whole pump needs to be submerged ie if i was to mount it on the bottom of the tank it should be right? any one know how these go in a stagea 260rs 1999?how do these wire up?

Edited by R33huntme
XKLABA Grand Master

XKLABA

Posted
Posted

Dave posted saying he knows how to "fix it" and he does, last time I was at Enique I was shown why they don't work when not submerged and it is a quick simple thing to fix, shot Dave a pm and I sure he would be willing to explain it, he is a really nice guy if you don't make yourself come across as a f**k stick

Hadouken Grand Master

Hadouken

Posted
  • Author
Posted

Lol, thanks.

He actually took the liberty of pm'ing me. He did inform me to block off 1 of the two holes associated with the priming system. Now thats all good and well, but leave that pump for long enough unsubmerged and the fuel leaks out again.

Either way, we tested them, saw how they worked, blocked off holes, submerged it, left it out of fuel, we did everything bar taking the bloody thing apart.

Its a shame they have to be modified. But I dont mind the 044. Still quiter than my stock pump I had. haha.

T04GTR Grand Master

T04GTR

Posted
Posted

yes, quick and easy fix. and they are on special at vpw for like 120 dollars..

hopfully they realise this fault and re-design the inlet acordingly. you cant just block them up either as it doesnt alow for the pump to self prime. if they are fully submerged the whole time there output goes up heaps with both the bleed holes blocked. :0

  • 3 months later...
DVS JEZ Grand Master

DVS JEZ

Posted
Posted

Just installed 1 into r33 GTR. So far no issue's even on empty but testing to see.

Looking at how hight the pump sits in tank i would think it needs alot more than 1/4 tank to be submerged.

What is the mod that u speak of Dave?

gtraaron Mentor

gtraaron

Posted
Posted

Just installed 1 into r33 GTR. So far no issue's even on empty but testing to see.

Looking at how hight the pump sits in tank i would think it needs alot more than 1/4 tank to be submerged.

What is the mod that u speak of Dave?

My fuel light is on and it is still fine Jez
Hadouken Grand Master

Hadouken

Posted
  • Author
Posted

If they dont have the bleed holes then they will work.

Also remember that the car drove fine all the way to empty. But as soon as you shut it off and leave it for an hour (enough time for the fuel pump to bleed off) then the car would not start with approx 15l in the tank

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