Best way to identify source of fuel leak?

[AC_Schnitzel]

You can always replace them so you are 100% sure it's not the lines.

I replaced my fuel lines yesterday and I paid 27€ for 3 meters of line at my local parts store. Beats having to wait for it to arrive though.

So I found the source of the leak — it is in fact at the junction of the supply hose here:



It might be that whoever installed the line used the wrong clamp...

Gonna change out the lines anyway.

Thanks everyone for your help!

[D.Martijn]

Ah yes. I thought I was onto something...

Anyhow, 5/16 EFI line at local auto parts store is more expensive by the meter than on FCP.


Sent from my iPhone using Tapatalk

You can always replace them so you are 100% sure it's not the lines.
I replaced my fuel lines yesterday and I paid 27€ for 3 meters of line at my local parts store. Beats having to wait for it to arrive though.

[AC_Schnitzel]

Is it the "Not for fuel injection systems" that you are talking about?
When you google, 30R7 which is printed on the hose, it says it's rated at 50psi (3,5 bar).
The fuel system on the E30 only works at about 3bar so those lines should be good.

Ah yes. I thought I was onto something...

Anyhow, 5/16 EFI line at local auto parts store is more expensive by the meter than on FCP.


Sent from my iPhone using Tapatalk

[D.Martijn]

Is it the "Not for fuel injection systems" that you are talking about?
When you google, 30R7 which is printed on the hose, it says it's rated at 50psi (3,5 bar).
The fuel system on the E30 only works at about 3bar so those lines should be good.

[AC_Schnitzel]

I think I might have found the source of the leak...

This is the supply line to the fuel rail — previous owner had it replaced w/ this at some point.

Haven’t started the car yet to confirm, but take a look:





Sent from my iPhone using Tapatalk

[jeffnhiscars]

5m will do both engine compartment lines for 2 cars

[jgilber0]

For sure -- I'll order the roll from FCP.

Noob question incoming:

When I go to remove these fuel lines, how do I minimize the amount of fuel spillage, and also reduce the pressure in the lines so that I can more-easily take them off?

I let my car sit a few days before starting the job, and there was no pressure when I removed the lines.

I had almost no spillage, you can use forceps to pinch off the lines if you’re concerned.

[AC_Schnitzel]

8X13 mm is the correct hose. 5 m is enough with some left over. The other hose is actually 5.5 mm...too small.

For sure -- I'll order the roll from FCP.

Noob question incoming:

When I go to remove these fuel lines, how do I minimize the amount of fuel spillage, and also reduce the pressure in the lines so that I can more-easily take them off?

[dnguyen1963]

thanks for your responses.

Any idea if this is the right part + enough length? https://www.fcpeuro.com/products/bmw...13311722262-5m

Is 5 meters enough to do the entire car?

EDIT: there are other fuel hoses varying in inner/outer diameters labeled as "braided fuel/vacuum hose" -- https://www.fcpeuro.com/products/bra...m-od-x-30mm-id

What are the differences?

8X13 mm is the correct hose. 5 m is enough with some left over. The other hose is actually 5.5 mm...too small.

[AC_Schnitzel]

thanks for your responses.

Any idea if this is the right part + enough length? https://www.fcpeuro.com/products/bmw...13311722262-5m

Is 5 meters enough to do the entire car?

EDIT: there are other fuel hoses varying in inner/outer diameters labeled as "braided fuel/vacuum hose" -- https://www.fcpeuro.com/products/bra...m-od-x-30mm-id

What are the differences?

[dnguyen1963]

Hey guys,

The EFI hose is not made by BMW or Autozone. They are made by other companies and would have to meet very stringent requirements. Imagine if there is a fire and it is traced back to the fuel hose...the liability is enormous.

[george graves]

I'll just echo what people said. Factory quality EFI fuel lines cost $$$. But cheaping out is a bad idea. Autozone will sell you anything, but the trust on it is very low.

If you park your car in an attached garage, all the more reason to get the real stuff. Then it's not just a leak, it can be a fire/life hazard. Just my 2 cents.

[jeffnhiscars]

It's 8x13mm but I've bought some at the dealer which was 5/16 (which Napa sells for less). Either way it's bulk hose so you don't need a PN

[jgilber0]

I bought BMW fuel line from BAVAuto, in three or four different sizes. Make sure that what you buy is high pressure EFI rated. I can’t remember all the part numbers anymore, but RealOEM was instrumental.

Check your system carefully before ordering, RealOEM showed a split system that sent fuel to both the front and rear of the fuel rail through a Y splitter, but my 1992 M20 had only a single feed line going to the fuel rail at the front of the engine.

Good luck! While you are in there, you should also do all of your vacuum and cooling hoses if you haven’t already done so.

[AC_Schnitzel]

Agree. And you should do this sooner rather than later as there is risk of fire.

It took me about 2 hours to replace all of my engine bay fuel hoses, I suspect that others could do it faster. Not a big investment in time or parts for a big improvement in safety and peace of mind.

Sweet, do you have part numbers? Or did you just buy EFI fuel lines and cut/replace w/ the right hose clamps?