Another fuel pump topic...

[Fett]

After spending the entire day yesterday reading through old posts, I have decided to upgrade my fuel pump to a M400 spec one (Bosch 0580254979?) as I am getting a Remap by Trevor.

Sorry, I know fuel pumps have been done to death, but couldn’t find very much on upgrading to a 979 pump. Plus it doesn’t help the search function is always down. So...

Can anyone tell me if it is a straight forward swap or are they different connections? I have a Bosch 0580254 910 fitted at the moment. Also anybody know of a good place to source one? Some of the prices I found were quite high considering you can get an 044 much cheaper.

Any help/advice as always is appreciated.

[daddysumo]

Yes all the connections are the same.If you have read all the old posts then no need to cover old
ground with regards to wiring,feed and return hoses etc...

[Metalman]

Hi Marco, I've just updated my fuel pump post so you may find some of the info helpfull. You must be getting excited about having your car mapped after thursday night.

[Fett]

daddysumo said:

Yes all the connections are the same.If you have read all the old posts then no need to cover old
ground with regards to wiring,feed and return hoses etc...

Thanks Daddysumo. Yep, have done all the wiring mods etc. When you say "return hoses" do you mean the braided hoses to the filter? Remember reading that they perish but cant find the post again. If so do you know what sizes and length I will need?

Metalman said:

Hi Marco, I've just updated my fuel pump post so you may find some of the info helpfull. You must be getting excited about having your car mapped after thursday night.

Cheers Jason, I had a look but I think it would be major overkill for my application. Just looking for a stright swap that's a reliable step up from the 910, with out having to fiddle with changing connections etc. Yep really looking forward to it after seeing yours get done. Not looking for more power really, will be happy with it making what it's supposed to! But if there's 20-30 bhp going spare... Well it would be rude not to.

[Gadgeroonie]

did you already change the fuel pump wiring ?

you could leave the old pump in place and use the m400 pump also

Edited by Gadgeroonie on Sunday 15th July 19:55

[Fett]

Yes, have changed the wiring, putting in another fuse and relay (or at least an auto electrician did).

How would I go about adding the M400 pump? Would it be a bit overkill? Or is just for reliability?

[daddysumo]

Fett said:

daddysumo said:

Yes all the connections are the same.If you have read all the old posts then no need to cover old
ground with regards to wiring,feed and return hoses etc...

Thanks Daddysumo. Yep, have done all the wiring mods etc. When you say "return hoses" do you mean the braided hoses to the filter? Remember reading that they perish but cant find the post again. If so do you know what sizes and length I will need?


The return pipe from the fuel regulator to the fuel tank on a standard tank goes onto an alumininm pipe which
is welded into the tank. This can be very restrictive and leasds to the pump backing up, especially when you start pumping larger volumes.

[andygtt]

Fett said:

Yes, have changed the wiring, putting in another fuse and relay (or at least an auto electrician did).

How would I go about adding the M400 pump? Would it be a bit overkill? Or is just for reliability?

some fuel pumps require priming or a pressure into them to deliver their best (044 for example) so you add the new higher flow pump AFTER the original pump.

high pressure pumps flow drops as the pressure they need to deliver increases...so a stock pump will flow say 200litres at 3 bar but only 250litres at 4bar (example figures only)...
because the original pump is no longer having to hold the constant 3-4bar fuel rail it can flow more... also because the new pump is being primed it performes better so its a win win

Worth mentioning that if you used an 044 after a stock pump (ie kept everything as you have and just change the post pump fueling) then it should also be quiet and not buzzy.... might be better to go M400 if you can get one and make sure you pay close attention to the fuel return to the tank as Daddsumo says as this is a known issue on some cars, mine was also stupidly restrictive.

Id like to see someone who is fitting an 044 just fit it after the stock unit before they do what most do and change everthing as I think it would solve peoples buzzy pumps!

[Fett]

Thanks guys. I understand a bit better all those posts I read now.

Will try and source myself an M400 pump today and take a look at the return pipe.

[Gadgeroonie]

"Id like to see someone who is fitting an 044 just fit it after the stock unit before they do what most do and change everthing as I think it would solve peoples buzzy pumps!"

i fitted one to mine a few years ago - you can have a listen next time i see you

[R0162]

Gadgeroonie said:

"Id like to see someone who is fitting an 044 just fit it after the stock unit before they do what most do and change everthing as I think it would solve peoples buzzy pumps!"

i fitted one to mine a few years ago - you can have a listen next time i see you

It does mike, I wrote a thread about pressure feeding the Bosch 044 and ho it solves the buzzing, if people read up on the internet they will find that the Bosch 044 is designed to be fed by another pump and is not recommended to be stand alone.

[Gadgeroonie]

R0162 said:

It does mike, I wrote a thread about pressure feeding the Bosch 044 and ho it solves the buzzing, if people read up on the internet they will find that the Bosch 044 is designed to be fed by another pump and is not recommended to be stand alone.

i have been using this technique approx 15 years on various cars - in my opinion it does not always quieten the second pump

[R0162]

That depends on flow doesnt it,, if the bosch 044 is trying to pull 265litres but the feed is only providing 240?

To "pressure feed" the 044 then surely the feed pump must provide more than the 044 requires? I think thats why a pressurized return swirl pot works..its easy to provide more fuel than the 044 requires and its easy to set the return pressure on the swirl pot on the main tank..

Sorry i'm talking at cross purposes here, what i'm saying is i have proved pressure feeding the 044 via a swirl pot makes it quiet, not that feeding the 044 inline by a stock pump will make it quiet.

Edited by R0162 on Tuesday 17th July 13:49

[R0162]

Gadgeroonie said:

i have been using this technique approx 15 years on various cars - in my opinion it does not always quieten the second pump

I can only comment on the noble Mike.. i'm not refering to any other cars ...