Fuel pump connector leak

[DaniChambon]

Hi everyone, this is my first post here.

Last january I decided to buy my first car: a 1989 316i sedan. Even though I had no previous experience working on cars, owning an E30 has been a great experience.
A week ago I ran into my first 'big' problem. After getting a full tank of gas I parked the car on a slight incline and noticed that quite a bit of fuel was leaking from the rear passenger-side wheel area. After parking the car on flat ground the leaking stopped. My dad helped me with draining a bit of fuel into a jerrycan. After doing some research online we went to further inspect the problem. After removing the rear seat and exposing the top of the fuel pump we filled the car up again and noticed that there was fuel coming out of what I think is the fuel pump connector.


Looking at pictures online I couldn't find people who had the same connector as mine so I'm guessing a previous owner has put some DIY work into it?


The fuel is squirted out from the hole where the black and red wire are going into the plug.

This leads to a few questions:
- Has anyone else had the same problem?
- How should I go about fixing this problem?
- What are the OEM parts that I could use to turn this into a proper connection?

Any help is appreciated.

p.s. The fuel pump and rubber o-ring seem to be working just fine.

Kind regards,
Dani

[roguetoaster]

Looks like someone drilled through the connector housing, possibly to install a new fuel pump independently of the fuel pump hanger. Of course they could have been simply fixing a failed wiring connection, which is not uncommon. Whatever the case, they made a very poor choice to not seal the hole.

Ultimately, you probably want to replace the whole fuel pump assembly so you do not have to try and rig in a fix for the added hole. As to the connector, you can probably order the right part, but it is a common spacing type of connector and plugs from many different manufacturers actually fit.

[McGyver]

My first thought is the rubber o-ring is probably squished flat and leaking. Even if you think it's good, pulling the pump assembly may break whatever seal is left and cause a leak.

Your fuel pump assembly has definitely been modified. The easiest approach would be to use a gasoline safe RTV sealant to seal the hole on the top and bottom. The correct approach would be to replace the assembly (which can get pricy). I would start with RTV and replace the assembly when/if the pump fails.

You can pick your car in RealOEM and search for the correct part numbers:
https://www.realoem.com/bmw/enUS/par...9-E30-BMW-316i

Fuel supply --> Fuel Tank

[roguetoaster]

If you do elect to replace the assembly it's normally fine to get the cheapest possible pump/hanger assembly and not use the included pump.

Also, looking back at the pictures the fuel hose on the right really needs to be replaced and you should really replace every soft fuel line you can.

[McGyver]

If you do elect to replace the assembly it's normally fine to get the cheapest possible pump/hanger assembly and not use the included pump.

I wrote this on how to convert to a single fuel pump, but the info is also good for how to modify the old hanger to be used with an aftermarket fuel pump. (Please disregard my soldering, it's gotten significantly better in the past decade)

https://www.r3vlimited.com/board/forum/e30-technical-forums/e30-faq-and-diy/336596-diy-double-to-single-fuel-pump-conversion

[DaniChambon]

Thanks for the replies guys,

A few days ago I took out the fuel pump. There has indeed been driller a small hole for the wires to go through. The hole used tot be closed by a tiny plug on the inside, but the plug seems to have a crack in it. For now I have sealed the hole with some strong glue. I'm not proud of this fix, but it works for now. In the coming time I will keep a very close eye on it to see if it holds up. If it won't I will probably opt for the RTV sealant.

As for replacing the soft fuel lines, is that something you can do on your driveway, or do I need to drop the fuel tank and such?

Also for anyone reading this who is thinking about pulling out their fuelpump. Be extra carefull with the fuel filter. Mine came lose and fell into my almost full fuel tank lol. It took my dad and I almost half an hour to find it back. Then we had to take it out with the use of some kitchen pincers haha

[wiliie34]

Thanks for the replies guys,

A few days ago I took out the fuel pump. There has indeed been driller a small hole for the wires to go through. The hole used tot be closed by a tiny plug on the inside, but the plug seems to have a crack in it. For now I have sealed the hole with some strong glue. I'm not proud of this fix, but it works for now. In the coming time I will keep a very close eye on it to see if it holds up. If it won't I will probably opt for the RTV sealant.

As for replacing the soft fuel lines, uno online is that something you can do on your driveway, or do I need to drop the fuel tank and such?

Also for anyone reading this who is thinking about pulling out their fuelpump. Be extra carefull with the fuel filter. Mine came lose and fell into my almost full fuel tank lol. It took my dad and I almost half an hour to find it back. Then we had to take it out with the use of some kitchen pincers haha

I was about to pull out its fuel pump, lucky to have read your post, thanks for your reminder

[varg]

That hole will be a problem unless permanently sealed with epoxy. When you fill the tank entirely it's full up into the filler neck, I was reminded of this when my fuel pump failed at a gas station and pulling the lines resulted in a gush of fuel I wound up draining the tank by a couple of gallons before the repair.