twin fuel pump conversion

[northernjim]

Mine def was there in 2006 but has got marginally worse over time, now stutters on 3 RH corners just above qtr tank, whereas used to be well below qtr tank it would start.

Fuel pump getting weaker over time too?



I am not a technical man.... But is it possible to look inside the tank to see how everything is sitting?

[adem.csl]

:supz: the higher the G forces, the more the fuel sloshes about.....





Adam did you read the part where it says not all cars suffer from this?


I think the answer is that not all fuel pick ups sit in the same place in the tank....

they say prevention is better than cure!!!!!
imagine you get out there hit a hard corner and bang spluttering.wish i had done that conversion now.im only exploring the idea.bmw have already checked my tank as ive had fueling problems before.(down to exhast)
but your right to open the tank and check its all good costs nothing.thanx nice input:thumbs:

[mattCSLnut]

Fuel pump getting weaker over time too?

They do... mine use to cause fuel starvation around Brands Hatch coming through Clearways, a 180 degree off camber right hander, before the pit straight, with over 1/4 tank of fuel :banghead:
A replacement fuel pump from BMW sorted this issue and it's been fine ever since :smokin:

[adem.csl]

[QUOTE=shimmy;n521930]The harder you drive.........

love it shimmy.gonna try that!!!!:thumbs:


northernjim has a point.the previous owner has definately used this car on track.i may already have an uprated pump.
will pull it out over weekend

[Mike RT4]

I'm sure in my trawling through the site, I saw a post by "The Gorilla" about a cheap way of improving the starvation issue by fitting an extension T-pipe, but I can't find it. Might be worth dropping him a PM?

[trackm3_csl]

Details of the E36 M3 mod we used

http://www.pumpkininc.com/content/doc/guide/ag-8.pdf

[daniel_csl]

I run this on my E36 which had issues from half a tank, now it runs pretty much to empty. Installed by Uncle Benz off here. Worth a PM maybe.

[DuncanR]

then there is a wieght difference making left side heavier.so really best option is to sit the pump in a bowl that stays full at all times.

Would imagine no problem with weight as right side of car has a fook off big battery in it !:-D .. reminder to self, fit new battery to CSL !

[Neil M]

I'm sure in my trawling through the site, I saw a post by "The Gorilla" about a cheap way of improving the starvation issue by fitting an extension T-pipe, but I can't find it. Might be worth dropping him a PM?

Could it be this you were thinking of Mike?:

"I have found this thread fascinating.
To address any problem you need to understand
the cause.

The standard E46 petrol Tank pick up operates
from one side of the tank. ie] the fuel pump
is having to 'suck' the fuel as opposed to 'push'
it from one side only.

Thus when the pipe that the fuel is sucked up
to the fuel pump is not below the fuel
level, then air enters the fuel pump, fuel
pressure drops and the spluttering on
heavy cornering on 1/4 tank can and does
occur.

As the standard fuel pump is rated for 5 bar then
its only issue is fuel supply and what it pick
up is, ie] whatever the distance away from
the pump it still sucks up fuel.

So, if you had a short length of rubber fuel hose
fitted to the bottom of the existing fuel pick
up, then a 'T' fitting, and then another length of
fuel hose to the other side of the tank, which would
be no more than about 1.0 mtr in length, you would
ensure that the fuel pump was always able to suck
up fuel, which is the cause of the problem.

Although this is all internal to the tank, access via
the existing pump set up would be quite easy, and
you have to remove this to fit the CA solution
anyway.

The CA fix just creates another part that can go
wrong, adds more weight !!!!!! and the same
results can be achieved a lot simpler and a whole
lot cheaper.

Regards,
The Gorilla"

Hats off to the man in the furry suite :thumbs:

[Mike RT4]

Hi Neil,
Yes, that was the one .

Where was it LOL?

[shimmy]

I thought thee was a simple 'twin pick up' to the single pump upgrade option!

Ahem!

[Neil M]

Hi Neil,
Yes, that was the one .

Where was it LOL?

Lurking in the annals: a thread to a link and so on, add infinitum:thumbs:

[adem.csl]

They do... mine use to cause fuel starvation around Brands Hatch coming through Clearways, a 180 degree off camber right hander, before the pit straight, with over 1/4 tank of fuel :banghead:
A replacement fuel pump from BMW sorted this issue and it's been fine ever since :smokin:

Liking matts route.but I'm gonna stick a walbro 255lph pump in mine Just to be safe.I've had previous with bmw pumps giving up on me.thanx guys For all input.
Knowledge is power.!!!!!!

[cantfind1]

Could it be this you were thinking of Mike?:

"I have found this thread fascinating.
To address any problem you need to understand
the cause.

The standard E46 petrol Tank pick up operates
from one side of the tank. ie] the fuel pump
is having to 'suck' the fuel as opposed to 'push'
it from one side only.

Thus when the pipe that the fuel is sucked up
to the fuel pump is not below the fuel
level, then air enters the fuel pump, fuel
pressure drops and the spluttering on
heavy cornering on 1/4 tank can and does
occur.

As the standard fuel pump is rated for 5 bar then
its only issue is fuel supply and what it pick
up is, ie] whatever the distance away from
the pump it still sucks up fuel.

So, if you had a short length of rubber fuel hose
fitted to the bottom of the existing fuel pick
up, then a 'T' fitting, and then another length of
fuel hose to the other side of the tank, which would
be no more than about 1.0 mtr in length, you would
ensure that the fuel pump was always able to suck
up fuel, which is the cause of the problem.

Although this is all internal to the tank, access via
the existing pump set up would be quite easy, and
you have to remove this to fit the CA solution
anyway.

The CA fix just creates another part that can go
wrong, adds more weight !!!!!! and the same
results can be achieved a lot simpler and a whole
lot cheaper.

Regards,
The Gorilla"

Hats off to the man in the furry suite :thumbs:

Yep this is what I have done, I ditched the twin pump mod I had.....this way is much simpler, easy to fit and solves all fuelling issues....also doesn't effect the guage readings like the twin pump mod did. I have also fitted a Walbro pump however I found the car to run rich with the uprated pump which led to a power loss. I had to adjust the fuel trims in the ecu map to solve the rich running....

[adem.csl]

The Gorilla.Yes well put, however the fundamental floor in your plan is that the crap oem pump is not strong enough to suck fuel through lengths of hose around the tank hence why you install a second pump in place of the sender unit on the left hand side to push fuel to the right hand pump.


Hardly any extra weight as you are replacing the other unit with the same thing any way, it just has a pump in it which weighs grams!


The oem pump degrades over time and does not produce enough flow anyway, hence why i am going with the walbro conversion for piece of mind.


If you want to be tight the just do the walbro conversion and let it suck fuel through pipes from the left and right side of the tank.
Are you being serious?contradicts your posts.cantfind1