Inline fuel pump guide

[SamHendry]

hey everyone. I have a inline pump sitting in the garage, one that replaces the oe fuel filter. Planning fitting it in the coming weeks but want to research now to make easier later on. I remember someone made a diagram. Think it was prawn. Maybe its in his thread but not sure what page? If anyone can point me in the right direction I would appreciate very much! Cheers

 

[S3 Hilife]

I can't remember who drew it but here's the diagram mate

Steve

 

[IPG]

Or ... replace "red fuel pump power wire" with "blue fuel pump wire - feed from plug under rear bench seat or (from my readings) the 87/Diesel location at the relay holder"

 

[IPG]

I was think in to wire in power and fuse to this location. For neatness.
Would it work ok???

 

[SamHendry]

Thanks Steve and Ian. Makes sense now!

 

[IPG]

So I installed the in line fuel pump

I don't hear it buzzing. I still hear the in tank prime and buzz when engine on. Should this one be priming too??? Should I be able to feel it buzzing or something as it is very quiet???

Engine is running. So i know fuel is pumping around but I don't know if it will still flow fuel even if it's not running because of the in tank pump which is before the in line...

 

[S3 Hilife]

Yes you should definitely hear it prime and run, first thing to do is check you have voltage from terminal 30 on the relay to the pump. If you do then your pump may be faulty. If not there may be a wiring issue or faulty relay.




Steve

 

[scotty_24]

Mine buzzes its nuts off on prime (so I know its working!) And then once the engines running its loud too!
You can hear it when your driving unless full chat.

However, Ive found that when less that 1/4 of a tank, and you go to start there is no buzzing prime sound.
I checked my lives and earths and they were good, so have the fuel pump a tap and it started buzzing!

So my thoughts are that they don't like low fuel levels?

It primes loudly and runs loudly EVERY time when over 1/4 of a tank.

My pump is a DA31 with Badger 5 fittings wired up as per Prawns diagram.

 

[S3 Hilife]

However, Ive found that when less that 1/4 of a tank, and you go to start there is no buzzing prime sound.
I checked my lives and earths and they were good, so have the fuel pump a tap and it started buzzing!

So my thoughts are that they don't like low fuel levels?

Hmm, that's a bit strange. Can't say I've ever had that problem with it

Out of interest have you noticed if it ever starts/stops when driving if the fuel level is low or does it just not work at all until you stick some more fuel in?





Steve

 

[scotty_24]

No once its running its running (or makes a noise like its running)
Its just the odd time the fuel level is low, if i dont hear it prime i give it a tap and then turn the key again and all is ok.

It never stops "buzzing" while im driving, ever.

 

[Prawn]

Check there's a fuse in the fuse holder! I did that when I first installed mine

If there is no power to the pump, the intank will still be able to pump through it and the engine will run OK. if the inline is working, you will DEFINITELY hear it.

 

[Prawn]

Mine buzzes its nuts off on prime (so I know its working!) And then once the engines running its loud too!
You can hear it when your driving unless full chat.

However, Ive found that when less that 1/4 of a tank, and you go to start there is no buzzing prime sound.
I checked my lives and earths and they were good, so have the fuel pump a tap and it started buzzing!

So my thoughts are that they don't like low fuel levels?

It primes loudly and runs loudly EVERY time when over 1/4 of a tank.

My pump is a DA31 with Badger 5 fittings wired up as per Prawns diagram.

That's VERY odd mate.

my car rarely gets over a 1/4 tank and its always buzzing away

One tip is to wrap the pump in an offcut of silicon hose to dull the vibrations and take the edge off the noise.

On idle you can hear mine above the engine quiet easily, but once driving I don't really hear it much.

 

[scotty_24]

yeah mines wrapped in a cut silicone hose totry and deaden the buzzing noise.

Its very intermittent when it doesn't fire up, and coincidentally is always when the fuels lw and the lights on!

When the tanks full, there are no issues!

 

[scotty_24]

When im driving slow steady speeds I can hear the DA31 buzzing away in the background, but full attack on track you cant hear it.

Ive logged fuel and all is ok so the DA31 is supplying fuel.
My first check when I stop after a session is to hear the DA31 on my cool down lap to make sure she's still running.

 

[IPG]

Check there's a fuse in the fuse holder! I did that when I first installed mine

If there is no power to the pump, the intank will still be able to pump through it and the engine will run OK. if the inline is working, you will DEFINITELY hear it.

Thanks everyone for your input.

Yeah I think i have a wiring fault. Was trying out some new heat shrink connectors with solder built into them. I think that may be the issue.

Will report back tomorrow.

 

[IPG]

I have 87 and 30 the other way around from Prawns diagram...

I have done it like the non hand drawn diagram I posted. Could that be the issue?!?

 

[<tuffty/>]

I wired my relay to switch from the pump feed in the fuse box... primes on start at the same time as the intank

<tuffty/>

 

[IPG]

I wired my relay to switch from the pump feed in the fuse box... primes on start at the same time as the intank

<tuffty/>

so make a connection from the "87f/diesel" to pin 86 to the relay? that's what i've tried to do too

 

[Prawn]

87 and 86 should not be connected.

86 is the trigger, 87 is the inline pump supply.

87 and 30 being swapped makes no difference, it's just making a connection across the two.

on mine the pin 86 is wired to the pump supply at the tank, because my relay is back there. Pin 87 is straight from my battery.

If you link pin 86 to 87, instead of feeding 87 from a 'better' supply, you'll be loading the standard pump wire with 2 pumps, thus overloading the wiring and usually giving voltage drop.

 

[IPG]

87 and 86 should not be connected.

86 is the trigger, 87 is the inline pump supply.

87 and 30 being swapped makes no difference, it's just making a connection across the two.

on mine the pin 86 is wired to the pump supply at the tank, because my relay is back there. Pin 87 is straight from my battery.

If you link pin 86 to 87, instead of feeding 87 from a 'better' supply, you'll be loading the standard pump wire with 2 pumps, thus overloading the wiring and usually giving voltage drop.

ah maybe there's a misunderstanding

i was talking about using the "87f/diesel" from underneath the relay holder with something like a ring terminal joined to wire which would then connect to the relay at pin 86.... if that makes sense?

 

[<tuffty/>]

so make a connection from the "87f/diesel" to pin 86 to the relay? that's what i've tried to do too

Nope... I took main power off one of the 30's (you can take it from there, the battery or whatever as long as you fuse it) and the relay is switch from a wire off the back of the fused side of the intank fuel pump which I did in the actual fuse box... Prawns solution is much the same as mine only he took his from the rear (fnarrr) of the car near the pump... I wanted to keep my relays under the dash...
http://www.audi-sport.net/xf/threads/my-minor-modding-thread.76389/page-51#post-1870795

<tuffty/>

 

[IPG]

ooohhhhh right right... fuse number (i think) 28??? or something? it's a 15A fuse?

 

[<tuffty/>]

Sure... why not

<tuffty/>

 

[IPG]

Got it going.



Was just shonky wiring when using those wire joiners that are meant to crimp the wires in them. Never again.

 

[scotty_24]

Success! Thats the noise alright ha ha

Got it going.



Was just shonky wiring when using those wire joiners that are meant to crimp the wires in them. Never again.

 

[IPG]

I thought it would be much louder TBH.

Hardly can hear it when driving and radio/music on.

 

[scotty_24]

My cars stripped so i hear it a little more I guess

 

[SamHendry]

Finally getting round to fitting this.. What wire do you splice into on the oe fuel pump harness?

There's four wires.. Brown purple/black brown/white and blue/red

 

[IPG]

You're gunna be running power from the front of the car anyway so just use the wire from "diesel" point for the signal to the relay. I wanna say it's the blue/red

 

[SamHendry]

Blue/red got it Ian. I need to get some 30amp cable and an old bit of wire or coat hanger to feed the cable through the body.. Been putting this off for waaaay to long.. Mostly because I hate electrics even when it's as simple as this although I still don't understand it haha give me some spanners!

 

[IPG]

It's pretty simple. It's just finding a place for the wiring to quickly go back into the cabin.

If I were to do it again I would follow the fuel filter feed hard line. Feed through there from the top. Might need something stiff but very bendy at the same time soo the wire can make it past the 90 degree bend

 

[scotty_24]

I used a grommet on the rear seat bench that goes down to under the car (bit fiddly ) and appears right next to the oem fuel filter location.


I wish I had of spliced in at the relay at the front of the car for a neater job, I spliced into the fuel pump harness at the pump, wires all over the interior

 

[IPG]

i couldn't figure out where that grommet led to... hahaha

 

[scotty_24]

It was a nightmare, used a coathanger and just kept shoving with a mate lying under the car listening for the scraping noises haha

 

[hendo#1]

Drop the tank as low as you can on the 4 bolts that hold the straps onto the tank.

Makes life a little bit easier

 

[SamHendry]

Argh this sounds like a pain in the ****.. Ill give it a go tonight!

 

[SamHendry]

Got it on and wasn't to bad to do.. Dropped one side of the tank as hendo suggested which made pushing the wires through alot easier but unfortunately the second hand pump I bought is fcuked! I only paid 50 for it and it came with the B5 fitting and all the wiring so still was worth it.. Neeed a new pump tho grrr

 

[IPG]

DAMMIT!!! test it out.... hook up the wires to the battery??? sure it's dead?

 

[SamHendry]

It's a good idea Ian. I did try it but no luck, it makes slight noise but nothing like it should and it's very inconsistent.. It's bad basically fried. It's not genuine pump. Just a knock off piece of junk!

Need to find a pump. Where tho? Could only find knock off ones on eBay?

 

[<tuffty/>]

Bosch 044...
https://www.merlinmotorsport.co.uk/p/bosch-0580-254-044-fuel-injection-pump-580254044

Have had a DA-31 in mine for years..not sure what the eBay ones are like these days... chances are there are copies of copies on there now... I think its a case of make sure the returns policy is sound and see if feedback includes anyone buying a pump...

Only buy from a UK based supplier and preferably one that sells other 'performance car' stuff and has been a seller for a number of years... stand a chance of getting a decent one then and some decent support if it does go wrong..

<tuffty/>