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Inline fuel pump after intank lpfp setups

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Hi All

Kind of new here, being reading mainly.

I own a Audi A5 B8.5 2.0T EA888.3 engine similar to a MK7 Golf GTI just in a longitudinal setup.

The only difference is the complicated LPFP is uses.

Cars like the S4/S5 and probably other from around the same time like S6 and S7 use it also.

There are not simple upgrades available on the market for these.

Picture of pump in below link if anybody is curious.


So since we built the engine and stepped away from the OEM turbo and use a garrett turbo we could get bigger HP numbers out of the car.

The EU specs have DI and MPI on this car the MPI have being upgraded to 980ccm injectors.

Which is what is giving me fuelling issues, so the stock LPFP is being a roadblock right now.

I decided to try adding a AEM 400Lph inline and see if it would solve the fuelling issues.

It did solve the problem kind of.

At rev limit it still holds on 4.2Bar but before red line it tends to peak at 10Bar.

Knowing there is no return line I am expecting this to be an issue later on if ignored.

The other problem is when the door opens the intank LPFP primes, I tried using a signal from one of the cables on the intank pump to get the AEM one to prime also.

But no luck, so I am stuck finding a cable which can give me a signal without later on blowing a fuse and end up catastrophically.

During our test we just gave power to the pump after starting the car by plugging in the power on a relay switch.

So here is my hope someone on here could perhaps have some ideas that could work for this situation.

Was thinking about adding a surge tank also, but no idea if this would really change the situation.

Additional fuel lines would have to be added to do that.

And it being a still road legal car I kind of want to minimize on certain modifications.



That fuel pump looks to be the same as what we run in our Golfs, we upgrade the the LPFP to the Audi TTRS pump with the upgraded fuel pump control module as it demands quite a bit more voltage to run. These are more than capable of supplying our HPFP well over 700bhp. I'm currently adding staged port injection to my MK5 using the same pumps as above.

You need a separate control module for the pump you've added this is why your not getting the prime from the aftermarket pump, the system cant be piggy backed its just to much demand. I do think the TTRS is what you need though and a lot easier. You can use a PM4 controller that will work with any ECU and can run any 2 LPFPs, have a read up on them there literally plug and play.

here's a link to the controller you'd need to run the TTRS pump or any pump for that matter. There is a PM3 version depending how much you want from it in terms of manageability. have a shop around you may be able to find it cheaper.


hope this helps,


Attached Files

Hi Martin

I have being looking at the torqbyte solutions.

Was considering it a while ago but the guys at Torqbyte told me the PM4 for brusheless pumps(like the A4/A5/S4/S5) was discontinued.

Mainly because tuners had a lot of problems setting up the fueling, which from what I understood was done through their own software and no longer through the actual ECU.

Though the PM5 is supposed to be a better solution now which still allows you to due to fuelling through the stock ECU.

But there is very little information to be found about the PM5.

I am considering getting a PM5 with a DeatschWerks DW440. Not sure if the TTRS/RS3 LPFP basket can be put into the A5.

Haven't worked on any of those yet.


I don't want to doubt anyone or say otherwise but that is absolutely no true and PM4 is absolutely capable. There are many running the brushless pumps with the PM4. If you have a look at that link I sent it gives you the option for the brushless setup and how to wire it in, you can still do all the stock fueling through the ECU with the PM4. have a good read up on it i think thats pretty much the answer to your issue. I'm almost certain the TTRS pump fits btw, again install this with the PM4 and you'll be supplying more than it can ever demand.


Hi Martin

The PM4 was a option(well the only option) I was planning to go for for a long time.

But when I wanted to order everything from Torqbyte it was on backorder and eventually discontinued.

Torqbyte themselves and even some tuners starting telling me it was going to be problematic.

The way it was initially explained to me was that the fuelling no longer was done through the ECU but through the TB software.

Which was supposedly the issue people were having.

If the TTRS/RS3 pump can just be dropped into my tank. without modifications it will be probably be a simple solution.

So I would just need to order 8V0919087A and the PM4 or PM5 and should be good.

Since getting a DW440 means I have to somehow get that to fit into my basket.

This is the TTRS 8S/RS3 8V we are talking about right? Since the older gen looks different.

Below snippet of TB IG saying PM4 was canceled.


The PM4 can still be bought as well as the PM3? From reading that I think its the PM4 ran brushless he was referring to.

There's a few options here really, either way I suggest you ditch the OE pump if its giving that much issue.

1. Place the AEM pump you have into the existing OE housing and run the whole system off that (it will be more than capable) it may need a little fettling to fit though.

2. Use the TTRS pump as a whole drop in or you can swap the pump into your current housing as above.

3. scrap the idea of the AEM & TTRS pump and use the DW65 pump that's a direct replacement and designed to fit in the OE housing with no issues at all

All 3 ideas or anything pushing past the limits of the OE voltage/control will require some sort of fuel module upgrade.


I've just been on Torquebite myself and ordered 1?

Hi Martin

I think I am going to ditch the AEM solution.

Not sure if this pump can be used as an intank pump, I am assuming not since it refer to it as an inline pump.

I ordered a DW440 today which is a brushless pump that is supposed to be drop in.

Uses the same connector just need to repin it since the wiring order is different.

They send me instructions for that, so that will be my next attempt.

If the OEM controller cannot give the voltages I'll have to get the torqbyte anyway. But I'll have a pump already which is supported.

The TTRS pump will be the backup solution, if I end up ordering a TB I'll get the newer PM5 one.

Though they haven't answered yet if I should get the wiring loom for the TTRS/RS3 then or still the A5 one.

But unclear what is needed in that situation.

But with finally a little luck the DW440 will do the job.

However I'll probably upgrade the fuel lines also, just in case I'll run some ethanol blend eventually.

The trick now is to get the OEM pump out of the basket, so I can properly mount the DW440.

Sadly Audi loves to glue in the frame that holds the pump into the actual bucket.

So will probably be a challenge to get that done.


smart move on the pump mate! If you have a google search there's plenty people on the forums that have done the pump swap in the housings. Its really not hard at all just don't forget to prime/purge they pump/system, seen that cause issues in the past.

Unfortunately the LPFP is on it limits, your going to need a PM4 or equivalent regardless of what you uses so will definitely need it with the DW440 without it your going to hit nasty fuel cuts/lean conditions on boost. I wouldn't even risk it, its a 100% certain issue without.

So the controller isn't going to be able to handle the DW440 then?

Couldn't find any information what kind of amp's it could do. Which seem vital to what the pump will do.

Can see the flow/amp rate on the tech sheet, but no idea how much the OEM controller will do.

Guess I'll have to order the TB anyway.

Still have my previous pump, which started to fail.

So while I wait I can work on getting the basket prepped.

Though any idea what the top part attached to the pump hat?(right piece in the pictures from below link)

The actual bucket has the mounting bracket glued into from the looks of it.

Going to try to drill a hole in the top and cut it off with fishing wire or something.

And just glue it back with loctite or something.



Unfortunately not, these cars don't like anything other than what they came with, it needs a controller regardless.

I'm not sure what your referencing in regards to what goes on the top? Its all pretty straight forward and you'll see when you come to fit the new pump but you can glue but I just used the good old tried and tested cable tie. The controller is plug and play between the 2 plugs.

Good to know. I thought that they had some wiggle room considering the Golf 7 GTI/R can run a Walbro 535 on the stock controller.

Though those are not brushless so maybe there is a big difference in them.

What I mean with the top part.

When you pull the fuel pump basket.

You got the hat(top part) attached to the actual bucket which holds the pump.

It almost looks as if there is a second pump in there. Not sure if these things can be a limitation.