Walbro 400Lph Problem

[MrStabby]

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

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

[dori34]

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

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

women drivers

[DVS JEZ]

Haha come on

Foot flat to the floor, tyres squeeling hard corner in 2nd, change to 3rd foot flat still cornering. Thats all the tyres can handle.

[Hadouken]

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

[DVS JEZ]

Really. Thats alittle dissapointing.

[Hadouken]

More than a little disappointing Jez.

[GTScotT]

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]

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.

[R33huntme]

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 April 25, 2012 by R33huntme

[Hadouken]

Dont know what the tank setup is like on a stagea.

But yes it needs to submerged at all times

[XKLABA]

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]

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]

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

[DVS JEZ]

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]

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

[scotty nm35]

Good to know, but which model did you install? Was it the e85 version FP859?

[gtraaron]

Good to know, but which model did you install? Was it the e85 version FP859?

F90000262

[scotty nm35]

Ok, I have been buying the F90000267 pumps. These ones have no bleed holes and are completely sealed including the power wires. Yet to try them though.

[Hadouken]

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

[gtraaron]

Ok , i just went to start after sitting overnight and it did start but it was second go not first as normal as it had to prime and get fuel back in . (probly 8L or so In tank