# question about using a walbro inline fuel pump in place of2nd pump on mk2, (any input from vrt/1.8t guys welcome)



## smugfree3 (Feb 20, 2006)

no response from the mk2 guys:

i coming close to finishing up my 1.8t swap. on the last car i did, i just put the walbro after the 2nd fuel pump,
but for the sake of cleanliness, can i just use the walbro in place of the secondary pump?
is there any way that a walbro fits in the accumulator? or can i just go from intank pump->filter->walbro->motor?

im just worried that if the accumulator acts as something of a surge tank then wont the walbro outrun the intank pump and ill lose fueling capacity? if it helps to know, the motor is on a bigger turbo with 440's for injectors.


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## screwball (Dec 11, 2001)

The closest I've heard of people running inline's in conjunction w/ an intank is at the stock filter location by the rear wheel (on MK4s at least) and they'll throw the filters in the bay by the timing belt cover. Personally I run a TT pump w/ a non 044 Bosch inline up in my engine bay. I'm pushing 400wheel and I've never had a lean out condition that was pump related. I even killed my stock intank pump and while I wasn't boosting the crap out of the car until it was fixed, all was well.


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## FlatlanderSJ (Oct 4, 2007)

I have my vrt corrado running intank > walboro > filter > motor. the walboro was mounted next to the fuel filter in the rear. Running 22lbs on a 35r @4bar fpr and never had problems leaning out. remember when you decrease pressure on a pump the flow rate increases.


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## Capt.Dreadz (Jun 4, 2003)

I run mine Intank>filter>Pump>motor. I hate to think my 044 is sucking up dirty fuel.

And to answer you question...no, you can't fit the walbro in the stock location. I thought about it myself. If you're looking for a semi submerged setup, IE sells a dual & single surge tanks.


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## JettamiahMKIV (May 14, 2011)

*walbro intank*

what about a 255lph alone intank? intank >filter>motor?


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## Capt.Dreadz (Jun 4, 2003)

JettamiahMKIV said:


> what about a 255lph alone intank? intank >filter>motor?


2 intanks? :sly:


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## HidRo (Sep 19, 2003)

Capt.Dreadz said:


> 2 intanks? :sly:





JettamiahMKIV said:


> what about a 255lph alone intank?
> intank >filter>motor?


I think this way makes more sense?
I'm not sure, but the CIS intank pump can handle a 255lph "sucking" from them, so it's a + to have both, and I've read also that the fuel filter should be after as the 255lph it better at pushing than pulling fuel.


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## Nevaeh_Speed (Jul 9, 2004)

I have the stock mk2 intake, and a fuel filter right before the 255lph pump... Works fine. You just need to relay the 255lph as the stock harness to the second pump doesn't allow as much volts to make the pump work as it should. I used the stock harness to the old 2nd pump as the trigger wire and ground. Makes the job super easy.:thumbup:


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## kevinmacd (Sep 4, 2003)

i have a stock mk2 tank and brand new in tank supplying an 044 in the stock location then a factory filter to the motor. I also use the mk5 fuel pump control module to supply variable voltage to the 044 as per the 2.o fsi ecu. never had an issue running lean on my stage 3+ 2.0FSI


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## skybear (Sep 27, 2010)

Nevaeh_Speed said:


> You just need to relay the 255lph as the stock harness to the second pump doesn't allow as much volts to make the pump work as it should. QUOTE]
> 
> 
> Any more info on what you mean by doing this?


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## FlatlanderSJ (Oct 4, 2007)

MEKA NECK said:


> Nevaeh_Speed said:
> 
> 
> > You just need to relay the 255lph as the stock harness to the second pump doesn't allow as much volts to make the pump work as it should. QUOTE]
> ...


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## BarryV (Apr 23, 2001)

MEKA NECK said:


> Nevaeh_Speed said:
> 
> 
> > You just need to relay the 255lph as the stock harness to the second pump doesn't allow as much volts to make the pump work as it should.
> ...


 The harness that goes to the factory inline pump under the car has 4 wires - 2 are red and yellow, and 2 are brown. The browns are your ground, and I wired the ground for the relay, and the pump into those, using butt connectors. The yellow and red are your original 12 V feeds to the fuel pump. I cut those and butt connected the "relay signal" into them. 

When your car tells your in-tank and in line pumps to turn on, from the under dash relay, that 12 v signal is now used to tell the aftermarket relay under the car to push the 30A 12V direct feed to the Walbro.


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## Daskoupe (Oct 9, 2006)

I have not relayed my walbro.Thinking i should though


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## 01ttgt28 (Jun 23, 2009)

C2 motor sports sells a awesome kit for the walbro it connects to all the factory lines 
I ran mine Apr in tank and inline walbro then a filter:thumbup:


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## HidRo (Sep 19, 2003)

If you do not replay it, what can happen? 
I had Megasquirt connected to the output of the fuel pump relay, and I saw a bit of a drop in voltage. Minimum I've seen was like 12V. So, is this bad for the walbro? Will it not work as perfect as it should? 
How many lph can the walbro do @12v? For how many hp is it good for?


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## Jones84 (Sep 6, 2007)

Here is my Walbro set up on a mk2 in the stock pressure pump loction. Still running stock intake pump. I have pushed 25psi on 680cc injectors with out any issues.


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## HidRo (Sep 19, 2003)

And this connected to the stock power connection? No relay of any kind?


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## Jones84 (Sep 6, 2007)

Yes, all stock. I have never had any problem with it at all in the 2 years its been in.


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## Nevaeh_Speed (Jul 9, 2004)

You need to relay the fuel pump as the fuel pump works best at 14.4v, and if you test the oem wire from the bottom fuel pump you get much less voltage, thus you relay it. Also I have the fuel filter on the inlet side of the 255 not the out as stated in the walbro instructions.


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## Jones84 (Sep 6, 2007)

Nevaeh_Speed said:


> You need to relay the fuel pump as the fuel pump works best at 14.4v, and if you test the oem wire from the bottom fuel pump you get much less voltage, thus you relay it. Also I have the fuel filter on the inlet side of the 255 not the out as stated in the walbro instructions.


 Interesting, Its is a 12v pump and a alt is regulated to only put 13.5v to the car max. So not sure were you would get 14.4v from. Its Amps not volts that make it run better. 12v and 100amp will make it work great. were as 12v and 20amp it wont turn on. Not enuff power. 
All a relay does is take the load of the AMPS not volts. The car has a Stock FP relay in the fues block just for that reason. 
I am running a bosh 044 of the stock set up in my MK1 and have installed 5 walbros in customer cars all using the stock FP relay. I have never ever had any issues with the pump not working correct..


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## HidRo (Sep 19, 2003)

Thanks for the information Jones! 
Cheers!:beer:


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## big_hot_tamale (Dec 20, 2003)

resurrect....

good stuff above but I have a question....

if I don't have an in-tank pump....what's a recommended setup for ~300whp?

I assume the in-tank pump is needed to negate the lack of gravity feed so that the main pump stresses less?

I have a fuel cell installed in the spare tire well, and right now I'm using some cheap oem fox cis pump that feeds from one of the the bottom outlets of the cell, to a summit/whatever inline small FI filter to rail. with a 3.5bar fpr it idles at 50 psi but then drops to 40psi if I put my 4 bosch 440ccs at 100% duty cycle.

I picked up a walbro 225lph inline pump and am wondering...

1) just replace the cis pump with the walbro
2) install it inline, after the cis pump
3)install it at the 2nd cell outlet, parallel to the cis, and have it triggered on when i'm not at idle, because the cis one works just fine at idle

I forsee some expensive plumbing in option 3...


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## Optimus234 (Aug 19, 2002)

Bump.

Number one is exactly what i'am looking to do on me 1985 mk2 Scirocco.

Just want confirmation that it will work.


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## big_hot_tamale (Dec 20, 2003)

Optimus234 said:


> Bump.
> 
> Number one is exactly what i'am looking to do on me 1985 mk2 Scirocco.
> 
> Just want confirmation that it will work.


It's the option I went with, but no word yet on function as the engine is under for a ring and bearing change.


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## Optimus234 (Aug 19, 2002)

Please tell me what the outcome is when your car is running.

Thanks,

Kevin


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## HidRo (Sep 19, 2003)

In the end, I went with a direct connection from the battery, not the stock wiring through the fuse box.
It's working great.
I still have the lift pump from the tank, and the inline walbro


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## VWDugan (Mar 22, 2001)

I am looking at doing the Walbro pump in-line on my coupe...but the car was originally diesel...can i just leave the original lift pump in the tank and run the walbro inline or do i need to change the diesel one out?
I was originally going to swap out the tank for an mk3 unit but that seems like a pain to do lol


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## TwinScrew20v (Dec 25, 2003)

VWDugan said:


> I am looking at doing the Walbro pump in-line on my coupe...but the car was originally diesel...can i just leave the original lift pump in the tank and run the walbro inline or do i need to change the diesel one out?
> I was originally going to swap out the tank for an mk3 unit but that seems like a pain to do lol


Swapping the tank was actually pretty easy. Took about 5 hours including running the Mk3 hardlines to the front (but they you could get away with rubberlines fitting in the Mk2 lines if you wanted). I did this swap so I had a Mk3 pump feeding my Walbro, not to mention the extra capacity. I had an intank fail and lean out the motor and melt #6 at 13psi, but with a good intank, no need to worry. I didn't know the age of my intank so it was probably time.

As for fuel cell needs, gravity feed is fine in place of a transfer pump, but make sure your cell has a method of keeping fuel at the feed port. A lot of the ports are faced towards the rear since fuel goes that direction when you take off/shift, but you want to make sure you have a constant supply during cornering and braking as well. Baffles, or the fuel foam systems inside are what you want to watch for.


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