318is Fuel Feed Pipe from tank

[Jamese30]

Hi All,
Does anyone know which pipe it is from the internal fuel pump on the 318is that routes to the fuel filter then injector rail on the engine?

I have taken the inspection cover off from under the rear seat and there are 4 pipes. 1 on the left and 3 on the right. I assume 2 of these are returns (one being one that is not used) and 1 one is a feed and the last 1 is a breather??

Any advice would be appreciated.

Thanks,

James

[Jamese30]

Now have a picture uploaded as well....

[DeeDee]

Hello

Its the feed I'm guessing your trying to establish?
By the look of it there's two breathers or something there, ignore those. The ones coming from the fuel pump will be the feed and return, there is often directional arrows on top of the pump to indicate.

If not then simply undo one of the jubilee clips, get a friend to briefly turn on the ignition and see which way the petrol is flowing. Often handy to have something for the fuel to spill into.

[Jamese30]

Hi Dee Dee,
That's correct it is the feed I am after. I will look for the arrows tonight.

Interestingly there are three lines that run front to back under my car - one is unused?? One is the return and one is the feed. I guess the unused one is one of these feeds??


Thanks,

James

[DeeDee]

The unused one will be a breather I expect. Funny enough I am currently stripping an E34 and have a pipe coming from the tank and going the length of the car. However at one point it's simply stops where it has disintigrated (sp) away, then continues two feet further on!

If there are no arrows and you have nobody to turn the ignition while you watch, then you can often tell by the size of some parts. Again its hard to tell without seeing a larger image, but as a rule of thumb the feed will have larger fittings and the return will have smaller. i.e. if those bronze looking pipes have nuts attaching them into the pump, the feed would normally have a larger one. Hard to know if what I have said will make any sense to you! Sorry if not!

[Jamese30]

Hi Dee Dee,
Don't worry it all makes perfect sense. I will have a fiddle with it later and let you know.

It is very strange that they run breather pipes the full length of the car though... seems like an expensive way of engineering something..

[DeeDee]

Yes your right mate. Im new to beemers myself so havent got much of an idea about the reason for them, however Im sure some very clever and knowledgble person will be here soon to tell that they're something completely different and we should know better!

Got to love forums. Best of luck.

[MrWhite]

The longer curved pipe coming out the top of the pump is your fuel feed. The short one is the return. I'd wait for somebody else to confirm before you take my word for it though.

[Jamese30]

Just in from tinkering in the garage....

I can confirm it is the longer curved one . Thanks for all the help guys. Just need to get a bit of 8mm pipe now to replace it with!!

[DeeDee]

Good to hear mate!