Single in tank fuel pump conversion

[green]

Okay, so I probably didn't use the right search terms or something, but I'm looking for information on how to convert my '87 eta's dual fuel pump set up to the later single in-tank style. I thought I had to use one from a 318i but that's all I can remember.

[jlevie]

Use the pump from a late 318is.

[Gruelius]

done this before

Wiring different = easy

reuse early fuel sender

Pull the 10mm over tank fuel hose out from under the car (was kind of hard)

Push 8mm fuel hose from in the car accross the top of the tank and run down to the fuel lines spot (pain)

The hard line above the tank will now be your FEED to the fuel rail

The soft rubber line across the tank you just threaded will be a return now

hook those up accordingly to the 3 fuel lines under the car. i mixed them up myself... (the early style has feed/return in different spots) lol

[StereoInstaller1]

Why would you want to go from a good reliable setup to the shitty late style?

[Gruelius]

new transfer pump is like 200 bones tre pump nice and cheap for tighass e30 owners such as myself

[StereoInstaller1]

my transfer pump has been dead for years.

E30 does not need. Early main pumps last forever, apparently.

[Gruelius]

the main ones get noisy as shit and then die. but yeah mine was working without transfer pump for 1/2 a year+

[green]

Why would you want to go from a good reliable setup to the shitty late style?

Oh, I thought that going to the later single in tank style was better since the fuel pump is cooled in the tank whereas (my) early style is outside. Heck, if that's the case, maybe I'll just buy a new external main pump, install and call it good.

[dnguyen1963]

Internal is just a transfer pump. Most of the work is done by the external. When the tank is full, the external does not require much help from the transfer pump; however, below half empty the car really needs the transfer pump working.

[jlevie]

The possibilities for a loud external pump are:

A dead transfer pump that forces the high pressure pump to work too hard
A worn high pressure pump
A rusty fuel tank (very common)

While a dead transfer pump won't prevent the high pressure pump from working, operation may be iffy when the fuel level falls to below 3/4-1/2 full.

[603Racing]

OP, do more parts searching. I found an early transfer pump for less than $100 shipped, new. I'd tell you where, but that would be too easy. :) I will tell you I found the same setup for less than $100 shipped from 3 different online suppliers.

[StereoInstaller1]

I know this is an old thread, but Im approaching the same situation. My external pump is loud AF and sounds like its going to die any day now. I was thinking of doing the late 318i single pump conversion but am not to good with rerouting tubes or pipes so thats out of the question. Im a little confused about the setup of the 86 325e - So the external pump is really loud because its doing all the work since the internal pump (under rear seat) is most likely dead? I was thinking I had to replace both, but up above some say that one of their pumps have been dead for awhile and has been fine? Which pump has been dead, the internal or external? If I replace the external one that's making all the noise, is it just going to wear out again if the internal isn't replaced or working?

Thanks!

Perfect use of thread bump, intelligent questions, great responses...welcome to R3V.

[rex]

OP, do more parts searching. I found an early transfer pump for less than $100 shipped, new. I'd tell you where, but that would be too easy. :) I will tell you I found the same setup for less than $100 shipped from 3 different online suppliers.

This?

http://www.amazon.com/Airtex-E8141H-...productDetails

I just did the vega pump in mine, cost about 55 for the pump and strainer, for an extra $35 bucks I would way rather have bought that. Even comes with a new o-ring... Oh well. Live and learn

[dnguyen1963]

Do not buy AirTex pumps. They will last for only six months.