USP Low Pressure fuel pump Review

[scotth07a4sline]

I figured i would try the pump out as i was already running lean from my stock set up. Let me start with the fitment, I understand Audi changes stuff all the time without notice so i don't hold them responsible for the small fitment issue i had. I guess Audi decided to change the location of the top of the pump at some point because the location that is described to use in the online instructions puts the alignment pins on the others side. Which turns the top of the pump and turns the actual basket and pump sideways. With a little dremel work i managed to get them back to the stock position. (This is not their fault, just heads up for some people that might have the same stock pump configuration that i do). other than that minor issue pump was pretty easy to switch out.

Once the pump was installed i primed it and let it run, cycle through a little and let my car warm up. I've been working with EPY on tuning my car and is doing a very fine job[:)] So i ran some logs and this is what i came up with for the pump!

http://www.audizine.com/gallery/data/500/fuel_pump_graph.png

http://www.audizine.com/gallery/data/500/fuel_pump_graph_2.png

http://www.audizine.com/gallery/data/500/fuel_pump_graph_3.png

The pump was advertised to flow 50% over the stock pump. And it seems to not be doing that at all. The part that is frustrating is that for a $500+ product i was hoping to get some help as to why its not doing what was advertised. I feel as though i'm getting the run around after i sent them the log hoping they would look at it and tell me why its not keeping up. Has anyone else installed a pump and success with it at all??

[Don Supreme]

When I first looked at the graph I was like........ Hmmmm, did he post the before graph (stock LPFP).

Thats not looking good at all. I would resist going WOT because you a running crazy lean!

[kloeb2]

Wow, that looks about the same, maybe even worse than what my logs look like. I was looking at this pump as a possible solution to my problem, but now i'm not so sure... There has to be something else going on or a tuning issue somewhere.

[scotth07a4sline]

When I first looked at the graph I was like........ Hmmmm, did he post the before graph (stock LPFP).

Thats not looking good at all. I would resist going WOT because you a running crazy lean!

Yeah I know I just dont understand why this pump is just falling on its face

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[scotth07a4sline]

Wow, that looks about the same, maybe even worse than what my logs look like. I was looking at this pump as a possible solution to my problem, but now i'm not so sure... There has to be something else going on or a tuning issue somewhere.

Yeah I was really hoping to push some good numbers but it seems that just isnt going to happen with this setup although im still waiting on my rs4 controller to have what I thought would be the ultimate setup but I guess not lol

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[kloeb2]

Thats another thing that I don't understand though. As mec (i think it was mec) mentioned in USP's product thread, why do you need the rs4 controller with this pump? (Well, we might see why now). Isn't the point of USP's setup to use a pump that will flow more at the same duty cycle as the OEM lpfp? Where as, using the rs4 controller with the stock pump pushes the stock pump to higher duty cycles?

I was under the impression that this pump and the rs4 controller wouldn't need to be used together unless you're pushing insane power levels.

[kloeb2]

Are you using maestro? Could you send me your tune??? :) pretty please :)

[scotth07a4sline]

Well since I'm running lean I will was hoping to get the pump to fix that and then use the rs4 controller to push the pump more:) but I can't even get past lean yet:banghead:

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[rarak69]

In the final image,

blue line = specified
red line = actual
"load %" = LPFP duty cyle?

[jimrobbington]

I thought you had to have the RS4 controller for the LPFP to behave any differently than stock? I don't think tuning can control the LPFP pressure without a different controller?

[mec]

where is usp on this?

[drumnjuny]

i had my extreme doubts...

[scotth07a4sline]

I would really like to see what they have to say

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[rarak69]

I thought you had to have the RS4 controller for the LPFP to behave any differently than stock? I don't think tuning can control the LPFP pressure without a different controller?

Yes you can control the LPFP through the ecu no problem.





I have not seen results like this, actually i have seen some lower pressure numbers but nowhere near these results he is seeing, it may be a faulty unit, or possible a "bad" LPFP controller, if that Load% in his graph that i asked about it the duty, then something is wrong

[ericpaulyoung]

That green dotted line is the duty %, which is confusing me. Actually what is confusing me more is that the specified pressure is decreasing with in increasing rpm, but his tune does not specify this? Why would the ECU specify less pressure as rpm increases?

Eric

[ultraleggera a4]

Well since I'm running lean I will was hoping to get the pump to fix that and then use the rs4 controller to push the pump more:) but I can't even get past lean yet:banghead:

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When are you going to get the rs4 controller in the car because I'm thinking about getting it, I would really appreciate some logs if you get around to it.

[Firefox250]

Any updates?

[kloeb2]

Bump for updates and usp's response...

[fly300kts]

Bump for updates and usp's response...

Yeah right......

Phil

[mec]

I'm surprised they haven't chimed in has someone let them know about this thread?

[ericpaulyoung]

It is a little quiet in here.

Eric

[scotth07a4sline]

Still waiting for my rs4 controller:banghead: ecs keeps pushing their arrival date back.

Ive also been busy with my other motor tear down, I managed to find a motor out of a gti for $150 :)

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[mec]

how much was it from ECS? cancel your order if it's more than $230, that's what I got mine for on GAP.

[jimrobbington]

how much was it from ECS? cancel your order if it's more than $230, that's what I got mine for on GAP.

HAHA, I always use ECS to find part numbers, then I search GAP for the part number. It's usually 15%-20% cheaper.

[scotth07a4sline]

how much was it from ECS? cancel your order if it's more than $230, that's what I got mine for on GAP.


HAHA, I always use ECS to find part numbers, then I search GAP for the part number. It's usually 15%-20% cheaper.

Wow I guess I should have did a little more shopping around it was 290 and some change!!! ECS was usually my go to but I think im going to have to make a switch. Definitely canceling!

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[mec]

Wow I guess I should have did a little more shopping around it was 290 and some change!!! ECS was usually my go to but I think im going to have to make a switch. Definitely canceling!

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ecs should never be your go to, their shipping is insane and their prices are MSRP, if I wanted msrp I would avoid shipping and go straight to my dealer. Always use Genuineaudiparts, worldimpex, autohausaz, germanautoparts, etc. They usually are much cheaper.

[drumnjuny]

yup and any distributor will be importing the part from germany. but GAP charges the same $20 shipping rate (i think very reasonable for shipping from germany, the box isnt that small) for two, so martin and I saved $10 on shipping... (find a buddy and split it if you can)

[scotth07a4sline]

I bought the pump and a couple gaskets I needed and didnt get over $250 shipped. Thanks for pointing me in a better direction haha

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[scotth07a4sline]

USP where are you on this.....anything?

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[Charles.waite]

So if the lpfp is controlled by the ecu, and duty cycle is determined by a requested pressure value in the ecu, why do you think the pump underperforming is usp's fault? Sounds like a tune issue to me. You test pump flow rate by having it pump a fluid from one container to another and measure flow/time.

If you really want to investigate rather than witch hunt, then you would do that. Also I suspect your running lean issues have less to do with fuelling than they do with a bad tune or something.

So hook your OEM pump up to a constant 12v source and get a few Home Depot racing buckets and have it transfer water from one bucket to another and measure the amount transferred after say 10 seconds or 30 seconds. Then do the same with the USP pump.

Also what rail valve so you have? And what is your tune requesting?

Getting a larger pump and expecting it to add 50% flow with no other changes is like throwing in a set of s3 injectors on a stock engine and expecting power gains...

[ericpaulyoung]

If you look at the 3rd graph, there are two areas.
1. Before 4000 rpms
2. After 4000 rpms

USP needs to comment on what is happening before 4000 rpms. USP advertise that their drop in pump will increase flow over the OEM pump without any other changes. However, without making any changes to Scott's tune, the USP pump preforms actually worse then the OEM pump! Most importantly, the requested pressure before 4000 rpms is NEVER met by the USP pump, even at the low end.

Now Item 2 is the thing that is confusing me. I am helping Scott with his tuning, and the requested pressure dropping off after 4000 rpms is weird. The thing is, his tune does not request less than 5 bar at any time in the maps, so it is confusing to me. To try to fix this, we bumped up his requested pressure and the specified duty vs flow, and still not working. I don't know if the ECU sees that the pump is always underperforming and requests less pressure to try to protect the pump, or if there is something else that I am missing.


So in short, there are two items here, one is with hardware that is not performing as advertised, and the other a gremlin in the tune. Since the only thing that changed was the USP pump, it implies that the pump feedback is somehow screwing with the ECU requested pressure. If anybody knows exactly how the ECU and the pump controller/pump interact, I would love them to look at this. But it looks like whatever USP changed in the pump made it worse rather then better.

[jsandor91]

semi related question.

can my boost maanger plus control a aftermarket pump without the use of a rs4 controller?

[Charles.waite]

If you look at the 3rd graph, there are two areas.
1. Before 4000 rpms
2. After 4000 rpms

USP needs to comment on what is happening before 4000 rpms. USP advertise that their drop in pump will increase flow over the OEM pump without any other changes. However, without making any changes to Scott's tune, the USP pump preforms actually worse then the OEM pump! Most importantly, the requested pressure before 4000 rpms is NEVER met by the USP pump, even at the low end.

Now Item 2 is the thing that is confusing me. I am helping Scott with his tuning, and the requested pressure dropping off after 4000 rpms is weird. The thing is, his tune does not request less than 5 bar at any time in the maps, so it is confusing to me. To try to fix this, we bumped up his requested pressure and the specified duty vs flow, and still not working. I don't know if the ECU sees that the pump is always underperforming and requests less pressure to try to protect the pump, or if there is something else that I am missing.


So in short, there are two items here, one is with hardware that is not performing as advertised, and the other a gremlin in the tune. Since the only thing that changed was the USP pump, it implies that the pump feedback is somehow screwing with the ECU requested pressure. If anybody knows exactly how the ECU and the pump controller/pump interact, I would love them to look at this. But it looks like whatever USP changed in the pump made it worse rather then better.

Ahh, ok thats clearer. He should get in contact with USP directly, see if they can send him another unit. Sounds ridiculous for them to sell a worse performing pump that stock, could be a defective pump?

[mec]

semi related question.

can my boost maanger plus control a aftermarket pump without the use of a rs4 controller?

yep. the aux port is for the lpfp control

[Gregg@USP]

If I remember correctly you exchanged a few emails with me. I believe you stated the car is running close to 40psi of boost and you didnt have any dyno numbers on the car. At that psi the car should be making in the upper 500's at the wheels. Given your setup it is very possible that the 50% increase in flow is still not enough. Of course this will depend on your CR, BSFC, and tuning. The pump does flow the volume as advertised and has been tested in house on multiple big turbo projects and also by EPL on a B7 build they just did. Also what injectors are you running? You may also be out of injector too and that is causing the problem.

There is definitely something going on with the car and its hard to tell whether it is hardware or software related or just too much power for a pump at 289lph.

Regarding the request vs. actual pressure under 4000rpm, have you checked to make sure there are no leaks inside the tank. I would start there. Also you may want to look into how your requested pressure is mapped, requested pressure in your case looks like it is around 6 bar in the lower rpm range, usually requested pressure is closer to 5 bar. Its just really hard to tell the exact issue without more details and data on the car.

[ericpaulyoung]

Here is the boost plot for that same run. Notice that for his large frame turbo he doesn't get past 22 psi of boost before 4000 rpms, but after that he goes out of range for the OEM MAP sensor. The USP pump should be able to handle 22 psi of boost, and that is why I split the range into before and after 4000 rpms. I agree 40 psi is too much for the USP pump, but 22 psi should be easy cheese.



http://i1073.photobucket.com/albums/w381/ericpaulyoung/scottboost_zpsd4debc4c.jpg (http://s1073.photobucket.com/user/ericpaulyoung/media/scottboost_zpsd4debc4c.jpg.html)

[ericpaulyoung]

So comparing the third chart of this thread with the last one, you see that the USP pump is running 80% duty for less than 22 psi of boost (actually around 19 psi), and the pump is not keeping up.

There is something wrong here.

- Eric

[Gregg@USP]

So comparing the third chart of this thread with the last one, you see that the USP pump is running 80% duty for less than 22 psi of boost (actually around 19 psi), and the pump is not keeping up.

There is something wrong here.

- Eric

I see what you are saying. Without more data and specs on the car it is really hard to diagnose. It could be hardware related or could be software related. Best thing for the OP to do is to turn the boost down to around 25psi and do some more logs instead of trying to solve a problem at close to 40psi.

[ericpaulyoung]

I am thinking the same. He turned it down to 21 psi, but I haven't seen the new logs yet.

Eric

[ericpaulyoung]

OK, Scott pulled new logs with a 21 psi curve. After 4000 rpms, the same odd thing happens where the requested pressure is decreasing with increasing rpms. But also we have the same thing happening under 4000 rpms where the new pump is not keeping up.


http://i1073.photobucket.com/albums/w381/ericpaulyoung/scottlpfp21psi_zps72009ae6.jpg (http://s1073.photobucket.com/user/ericpaulyoung/media/scottlpfp21psi_zps72009ae6.jpg.html)

[ericpaulyoung]

There has to be something that is causing this odd behavior. Why would the pump produce less then OEM, and after 4000 the requested pressure drops down to 4.5 bar? Either way, the ECU should read a too low error and increase duty, but instead it is not reading an error, and instead it is keeping about the same difference everywhere.

Can USP comment on if they are tricking a signal to make the ECU think that it is under flowing, and then compensating the opposite direction? If so, is it possible that this pump was set the wrong way and it is reading that the pressure match when it is really under?

- Eric

[ericpaulyoung]

Here is the lambdas for that 21 psi run. Looks good until the end when the pump is too low and the injectors run out of fuel again. This is at 21 psi! Where is the low pressure fuel sensor? If it is in the pump I think USP just makes it read low to trick the ECU into trying harder. But if that is the trick to the modification, we have a faulty one here.


http://i1073.photobucket.com/albums/w381/ericpaulyoung/scottlambda21psi_zps9a1fdc17.png (http://s1073.photobucket.com/user/ericpaulyoung/media/scottlambda21psi_zps9a1fdc17.png.html)



And the boost


http://i1073.photobucket.com/albums/w381/ericpaulyoung/Scott21psicurve_zpsdf9a938b.jpg (http://s1073.photobucket.com/user/ericpaulyoung/media/Scott21psicurve_zpsdf9a938b.jpg.html)
- Eric

[choochb5]

Could very well be a fail safe. Not a very good one, if it is, since it's just protecting the pump instead of the motor. I wonder if the ecu is seeing duty rising too fast and just shuts it down. It does spike up pretty suddenly. It only starts to drop when it peak at ~80%. Might be a good question for Chris Tapp.

[jimrobbington]

I wish there was a way to make the k03 hold boost like that. I would be so happy.

[choochb5]

What about the fuel filter? Maybe the regulator in the fuel filter has failed?

Is it possible to log the LPFP pressure without starting the engine? Turn the key on to prime the system and see if it the pressure holds.

[Mc Suly]

damn i hope it's not the pump/related to it.
very costly, i have the dw300 lpfp no problems! goes strong

[Charles.waite]

New fuel filter?

[ericpaulyoung]

Ya, he has a fresh filter. It is really confusing me :/

[ericpaulyoung]

So here is a log I took this morning of my car. I have a TTRS pump and an RS4 controller. Notice that even during my spirited morning drive that the pump duty never gets above 50%. I did not do any WOT pulls, but the point is that the ECU is able to chase the requested pressure accurately. Scott's is not chasing correctly.


http://i1073.photobucket.com/albums/w381/ericpaulyoung/ericV14normaldriving_zps833f040a.jpg (http://s1073.photobucket.com/user/ericpaulyoung/media/ericV14normaldriving_zps833f040a.jpg.html)

[ericpaulyoung]

FYI

The flat spot up front is me starting the car and sitting in the drive way. Then I pull out of the house and head out to the highway.

[Gregg@USP]

Can USP comment on if they are tricking a signal to make the ECU think that it is under flowing, and then compensating the opposite direction? If so, is it possible that this pump was set the wrong way and it is reading that the pressure match when it is really under?

- Eric

there is nothing done to trick the ecu with the pump. it is not possible the pump was sent the wrong way.

[ericpaulyoung]

there is nothing done to trick the ecu with the pump. it is not possible the pump was sent the wrong way.

Thank you for clearing that up. It was a grasping at straws theory, but it was the only working theory I could think of why changing the pump and this weird behavior could correspond in time.

Do you have any thoughts on why we are running such high duty numbers but not holding pressure?

[scotth07a4sline]

This is a real head scratcher when i kept getting the low pressure out of spec code when i started to tune with ray i replaced the low pressure sensor and fuel filter thinking that maybe ultimately the lpfp is on its last leg but put in the USP and it seems to be worse the only thing i haven't changed is the controller which i ordered from GAP and saved a good bit then when it was back ordered from ECS anyway here are 2 codes i pulled from some light driving. The first one i understand it and isn't a big deal right now but the second is the one that i have been getting since i started tuning
2 Trouble codes found;


Trouble code 1 ; P0299 Turbo/Super Charger Underboost
Trouble code 2 ; P310B Low Fuel Pressure regulation Fuel pressure outside specification

[scotth07a4sline]

I have the RS4 injectors, hpfp upgrade stage 2 pump 145 prv, USP low pressure pump, replaced the low pressure fuel sensor the one thats on the hpfp and changed the fuel filter. The only thing i feel like is left is to replace the controller which im waiting for the RS4 one and completely blow out the lines to make sure nothing is going on. when i put the USP pump in i took a vacuum and completely drained the tank of fuel which wasn't that much and i wiped the tank out by hand to make sure any dirt and the slightest particle was out of there then i filled it with fresh fuel. That was the last thing i wanted was to such up something into my new pump. So what else is there to replace with the fuel system sensors controllers anything at this point to figure out why im not getting fuel

[mec]

This is clearly a sign for the LPFP gods, we must buy all buy an rs4 lpfp controller and use much cheaper higher flowing pumps like the dw300 or simply swap to the ttrs lpfp!


save some coin and get all the power you need!

[kloeb2]

I think so. Bought my Rs4 controller from gap a couple days ago. Two weeks to import though. Ahh gonna have to keep baby footing it for a little longer.

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[ericpaulyoung]

Ya, man you have replaced everything. Gotta be the controller :/

[scotth07a4sline]

Rs4 controller arrived almost done with the install then going to run some logs and cross my fingers that it will help wake this pump up!!

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[ericpaulyoung]

Scott got the RS4 pump controller in, and it is having to run a lot less duty cycle to produce basically the conditions before (OEM controller peaked around 80% duty, and the RS4 peaks around 65% duty). However, the pump is still not keeping up anywhere, and the post 4000 rpm weirdness is still there. The first plot is the OEM controller and USP pump, and the second plot is the RS4 controller and the USP pump.


http://i1073.photobucket.com/albums/w381/ericpaulyoung/scottlpfp21psi_zps72009ae6.jpg (http://s1073.photobucket.com/user/ericpaulyoung/media/scottlpfp21psi_zps72009ae6.jpg.html)

http://i1073.photobucket.com/albums/w381/ericpaulyoung/scottlpfpwithrs4controller_zps490bfeaf.jpg (http://s1073.photobucket.com/user/ericpaulyoung/media/scottlpfpwithrs4controller_zps490bfeaf.jpg.html)

[scotth07a4sline]

Well as of now I'm not running lean at the moment but thats only at 22 psi now to see what the difference is between the two pumps now that the the variable of the controller being bad is out of the question with the rs4 controller being installed:) now yo burn up my half tank of gas just to switch a pump Lol :banghead:

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[ericpaulyoung]

Drive to the mountains! Hit a vineyard, return home fueless :)

[Operator]

Any update?

[drumnjuny]

Can USP provide any cases of this pump performing please