How do I find the right fuel pump for my car?

[jasonbk]

I was told that the occasional bucking/jerking when applying throttle slightly (Usually at around 3k rpm in any gear) could be fuel pump acting up.

I'm looking at realoem for my car(m20b25 swapped 91' 316i euro), but I'm getting bit confused here!

http://www.realoem.com/bmw/showparts.do?model=AB11&mospid=47251&btnr=16_0043&hg=16&fg=05

According to realoem, I have:

16141180233 (same one that goes into US spec 318i/is)

Or

16141184022 (same as late model 325i)..

Search found that I can either have 55 or 63L fuel tank - would that dictate the type of fuel pump that I have? If it is, how do I visually see if I have 55L tank?
How do I make sure if I have the right fuel pump?

[vpilarrt]

I would have said its the O2 sensor. How old is yours?

[TobyB]

Try this- look at the top of the tank, right side, where the pump lives.

If there are 3 fuel- sized lines going in(1) and out (2), it might be the 318 version.

if there are 2, 1 in and one return, the 325....

Just a guess, but the 318 got that extra return, and that might be the clue...

...or not, as the 316 mighta had an M40....

t

[jasonbk]

O2 censor is 10 months old so I'd say it's fairly new.

I had M40 before I got the swap done - I'll check the # of fuel lines later.