Upgraded LPFP solutions available Discussion

[rarak69]

So whats out there? honestly did some searching and googling and really didnt find much solid other than custom or something of those sorts. Found some talk of VAST, however thats no longer an option.


Probably see how well a 040 or 044 will mount in there, i currently have logged about 25k miles with a 044 in a customers car running on some custom fuel pump code, without issues. Its doing very well for not being a "supported" pump for our PWM signal fuel pump controllers.


Whats everyone doing with BT's around here?

If you have a custom setup, what was all required would be helpful to know. I intend to call 034 tomorrow and see if they can sort a solution for me :)

[fordyoz]

from what i read a few months ago, it the LPFP used to be thought of as a bottle neck, but it is not anymore, and the stock one is fine if working properly.

most BT builds on here are stock LPFP

im sure someone else can chime in with more help

[mec]

stock lpfp runs out at around 425awhp, around 350 you get problems and need to upgrade the controller or get BMP or similar electronic device. look at the DW-300 intank fuel pump, its supposed to be a decent upgrade.

[rarak69]

stock lpfp runs out at around 425awhp, around 350 you get problems and need to upgrade the controller or get BMP or similar electronic device. look at the DW-300 intank fuel pump, its supposed to be a decent upgrade.

As a tuner, i have surely pushed limits of stock pump on other platforms(mk5/a3/tt) 390hp with duty cycle tweaks. My pump is failing at this time in my DD, so obviously a upgrade is due.

425AWHP on the b7 pump is nice to know, have not personally had the chance to tune any powerful B7 platform cars yet so i wasnt aware. Thanks for that info.

I will look into that DW pump...and see whats involved with the swap.

[jimrobbington]

I am more interested in how to specifically diagnose the lpfp. Any insight, rarak? Like number of cranks before start, duty cycle at idle or under wot, etc...?

[DRAKLORE]

I have a DW300, it's nice quiet and easy to install. I got mine from Vast. I think I could get my hands on one but honestly I haven't pushed my car much past 350AHWP to know the merits of this pump vs stock
I think one could be had for 100$ ish I would have to doubl check though.

[rarak69]

I am more interested in how to specifically diagnose the lpfp. Any insight, rarak? Like number of cranks before start, duty cycle at idle or under wot, etc...?

I can grab logs, its still in there slowely dying. I run code to advance the pressure and duty cycle of the LPFP, it started fluctuating badly in the last week, like a totally bad PID loop. So i went back to stock values and it seems a bit better now.

If i dont "prime" the LPFP before starting car, it takes about 5 seconds of cranking and im seeing rail pressure drops in the last few weeks out of nowhere. I first swapped HPFP with another i had laying around and its the same situation, but now more pronounced fluctuation(its an autotech), which points me to LPFP from logs ive seen in the past from other vehicles.

Jim i can dig up some logs on my laptop(have a few hundred) that have lpfp duty and pressure in them and get them over to you if you want to compare.

[rarak69]

I have a DW300, it's nice quiet and easy to install. I got mine from Vast. I think I could get my hands on one but honestly I haven't pushed my car much past 350AHWP to know the merits of this pump vs stock
I think one could be had for 100$ ish I would have to doubl check though.

Shane,

What additional hardware was required for install into stock basket? Just a spacer sleeve like the walbros? rest is pretty boltup with standard stuff?

i think for walbro's in the b5/6 i just used a spacer foam "sleeve" and a strainer from a 5.0 Mustang at the autoparts store, it was a friction/pressure fit into the stock basket, ran it fine for a while for me.

[chris@fifteen52]

My lpfp I think is bad as well and hopefully the sensor on that pump as well. My fuel gauge has nit worked in a while and lately when low on fuel and I go wot on a hill or on a sharp right turn I get a fuel cut I am assuming from the fuel moving away from the pump and the pump not being strong enough to overcome the sloshing fuel.

[CorneliusRox]

I thought you could take a freeze frame of your LPFP and if it is above like 50% duty cycle, it is on it's way out?

[fordyoz]

^ at idle > ~70% or so is bad

[rarak69]

I thought you could take a freeze frame of your LPFP and if it is above like 50% duty cycle, it is on it's way out?

This may hold true on a stock ecu or stage1. I can log some stuff tomorrow.

[shiro1745]

Shane,

What additional hardware was required for install into stock basket? Just a spacer sleeve like the walbros? rest is pretty boltup with standard stuff?

i think for walbro's in the b5/6 i just used a spacer foam "sleeve" and a strainer from a 5.0 Mustang at the autoparts store, it was a friction/pressure fit into the stock basket, ran it fine for a while for me.

I want to know this too, I need to replace mine. I get around 80% duty cycle at startup until rpms settle and engine load is very high too 70-80%
then the duty cycle goes to ~65% and the engine load to ~25%

[shiro1745]

I have a DW300, it's nice quiet and easy to install. I got mine from Vast. I think I could get my hands on one but honestly I haven't pushed my car much past 350AHWP to know the merits of this pump vs stock
I think one could be had for 100$ ish I would have to doubl check though.

ignore my sms, I just saw this thread after texted you.

[Charles.waite]

The long cold cranking is usually due to a bad check valve, which I think is built into the pump. Its not usually a worrisome failure on its own, but even I'm experiencing it in my stock b7 so its annoying. I might replace the LPFP soon because it just makes me nervous when a fairly critical fueling system is failing in some way.

In my b6 the fuel pump was failing hardcore last spring. When the tank was low you would hear a high pitched squealing from the back seat. Actually you heard it almost all the time, haha. Tossed a new pump in and its been fine aside from a short walrus noise on cold startup (which is most likely from the fuel filter). The pumps are very similar, though not interchangeable obviously. I think the stock B6 pump is good to around 350hp or so. So it would make sense the b7's is good for incrementally more.

On the 1.8t platform, we've got quite a few upgrade option for fuel pumps, but because its the only pump in our system its a more critical upgrade if you're making lots of power. With the LPFP and HPFP in the 2.0t it gets a bit more complicated. Just be glad the b7 allows you to log fuel pressure within VCDS. the 1.8t doesn't have that sensor. Just Pump duty cycle...

[DRAKLORE]

Rarak/Shiro-

I sent the pump to vast for the swap into my cage... But honestly after looking at it, I'm pretty sure it literally drops right in lol

I think possibly a few tabs might just need to be trimmed.
Here is a pic I took when I got it back:



At this point I threw the top hat on and dropped it in to the car.




The whole process was easy, in fact the hardest part being getting the pump hold down ring back on.

The DW300 is not variable voltage, I haven't had a single complaint besides me fucking up the float so my gas gauge is a 1/16 of a tank off.
I'm about to hook up the BMP with thicker gauge wiring to the pump, at that point I should really be able to push this pumps limits.

[rarak69]

Thanks Shane.

Yea from my experience a standard pump does end up working just fine for our cars or any other with PWM controllers for the pump. Ill have to get this guy ordered up and see how this goes :)

[DRAKLORE]

Send me a PM and I'll see what I can do, let me know if you find them somewhere else. Maybe I can add this to my site for those curious/interested

[shiro1745]

What else is around the pump that can go bad? Cause at this point I'm thinking to get the oem which comes with everything, right? all the plastic enclosure, level sensor, etc. I don't want to get an aftermarket one then realize the level sensor or something else around it (if there's anything else) was bad.

[DRAKLORE]

Your level sensor is just related to your gas gauge, if that's reading correctly that's fine.

The other two components are the Pump itself and a few wires and then the controller.

[DRAKLORE]

The controller is not in the tank, it sits up tucked on top of the tank lol

[shiro1745]

Send me a PM and I'll see what I can do, let me know if you find them somewhere else. Maybe I can add this to my site for those curious/interested

Shane you should sell this as a package, an upgraded pump + the labor for installing it cause I'm sure it's not a big deal but if I never had one in my hand I have no idea how easy the swap is. You'd probably find enough to buy this as a drop in upgraded pump good for gazillion HP

[shiro1745]

Your level sensor is just related to your gas gauge, if that's reading correctly that's fine.

The other two components are the Pump itself and a few wires and then the controller.

I found this thread looking for my "high load at idle" problem and this guy had his S4 doing the exact thing as mine, it ended up, the dealership told him, to be a bad fuel level sensor which was sending a message to ecu that is out of gas and was trying to kill the engine. Now not sure how much of that is true, I'm just saying what he said.

[Charles.waite]

All you need to install a fuel pump in our car is a hammer and flathead. Seriously. Thats it.

[shiro1745]

All you need to install a fuel pump in our car is a hammer and flathead. Seriously. Thats it.

And somebody said not to have too much gas in the tank, mine is full, great , and I don't dive the car. Is there a way to empty the gas tank somehow without making a big mess?

[mec]

Ghetto siphon it out, just dont get it in your mouth

[okswerve16]

The controller is not in the tank, it sits up tucked on top of the tank lol

Correct you have to drop the fuel tank to get to it

Also any aftermarket fuel pump that is turbine driven will work fine with PWM, g-rotor type pumps are the ones that burn out fast under PWM

[shiro1745]

Ghetto siphon it out, just dont get it in your mouth

How would I do that? Isn't there a sort of a screen in the way?

I remember I tried that with another car(forgot what) and couldn't get the hose into the tank.

[mec]

Hmmm..I've never done it on our cars but on American cars you just drop a hose into the gas tank and start suction and it will continuously flow until you interrupt it.

[DRAKLORE]

There's a siphon catch in the filler neck, so
You'd have to take the rear seat off and remove the ring and feed a hose in for best results

[DRAKLORE]

Correct you have to drop the fuel tank to get to it

Also any aftermarket fuel pump that is turbine driven will work fine with PWM, g-rotor type pumps are the ones that burn out fast under PWM

Ok swerve- what type of pump is a DW-300?

[Charles.waite]

And somebody said not to have too much gas in the tank, mine is full, great , and I don't dive the car. Is there a way to empty the gas tank somehow without making a big mess?

You could jumper the pump on with a 12V source and disconnect the line before the fuel filter and drain it into a LARGE fuel can. Just an idea. A PC power supply would work nicely.

[okswerve16]

Ok swerve- what type of pump is a DW-300?

Turbine, http://www.deatschwerks.com/products...tank-fuel-pump, it says quiet and reliable turbine impellar~!

[DRAKLORE]

Well it has been quiet and reliable so far lol
Roughly 40k miles

[shiro1745]

The DW300 is not variable voltage, I haven't had a single complaint besides me fucking up the float so my gas gauge is a 1/16 of a tank off.
I'm about to hook up the BMP with thicker gauge wiring to the pump, at that point I should really be able to push this pumps limits.

So what's the difference between a variable voltage and non-variable voltage on this pumps? Just trying to understand AMAIC

[shiro1745]

Every thread about fueling left behind makes me sad. I wish we had a fueling guru explain B7 fueling system in detail.

[Charles.waite]

The B7 fuelling system is a mess. Port injection has so much less going on, its vastly easier to deal with. There are literally the pump, the injectors and the fuel pressure regulator/filter. So much less to go wrong. ESPECIALLY when multiple parts are defective from the factory as in the b7 fuelling system...

[shiro1745]

The B7 fuelling system is a mess. Port injection has so much less going on, its vastly easier to deal with. There are literally the pump, the injectors and the fuel pressure regulator/filter. So much less to go wrong. ESPECIALLY when multiple parts are defective from the factory as in the b7 fuelling system...

Unfortunately yes, how the hell do we find out/understand exactly whats' going on?

[rarak69]

What exactly do you need to know in detail about the fuel system?

[FLYINGLEGGS]

I didn't read through this whole thing, but I know you can definitely log your lpfp duty cycle. I've been told anything over 80% is bad.
My solution on my BT that peaks at a little over 26 psi now uses an FSI RS6 (V10 TT) lpfp.