E30 Single Fuel Pump Conversion

[curryinahurry 39]

Recently my E30's been cutting out randomly due to my fuel pumps failing.  Despite being a 89' model - my E30 appears to be on the 2 pump setup, with an in-tank pump and an external pump to provide line pressure.

I've done a bit of reading on the UK forums, and swapping to a single pump setup seems to be way to go.  I've picked up a TRE-340 which is commonly recommended for the job.  The plan is to swap the in-tank pump with the new pump and replace the external pump with a bypass.

Has anyone done this to their E30?  Is it necessary to upgrade the fuel line going from from the in-tank pump to the external pump? What other modifications did you have to do?

[polley 916]

Mine had same setup. I looked at changing it to single pump and looked like it was gonna be pain in the ass. The hose from the in tank to the high pressure pump is quite large in diameter and probably not rated for high pressure. So would definitely look at changing that.

[Lucan 196]

I'm doing the same thing in my PFL - bought a FL tank so I could move to a single in tank pump, but sure it could be done without going to that degree?

I've read that FL tanks use a siphon system internally rather that the cross pipe which somehow is an improvement? That and the pipe diameter Troy mentioned are the main reasons I bought the whole tank (plus to avoid starvation issues and that I found one cheap)

Wont be looking at it til Xmas when I have time off work though, so if you finish before then let us know how you get on!

Edited November 5, 2020 by Lucan

[curryinahurry 39]

On 11/5/2020 at 9:39 PM, Lucan said:

I'm doing the same thing in my PFL - bought a FL tank so I could move to a single in tank pump, but sure it could be done without going to that degree?

I've read that FL tanks use a siphon system internally rather that the cross pipe which somehow is an improvement? That and the pipe diameter Troy mentioned are the main reasons I bought the whole tank (plus to avoid starvation issues and that I found one cheap)

Wont be looking at it til Xmas when I have time off work though, so if you finish before then let us know how you get on!

Hey Lucan - mines a bit of a strange setup because mine is a 89 facelift model and its got the larger 63L tank.  But for some odd reason it still uses the old 2 pump system.  I think being an S.A built E30, they're a bit odd.

I've custom designed and fabricated a bracket to secure the pump and I've got a solution for connecting to the outlet without the reducer.  But haven't had got around to changing the fuel line to a smaller diameter - I will see if I can it without dropping the tank.  

Will take some photos and update once I've made more progress.  Hit me up if you need my custom bracket

[curryinahurry 39]

I ended up fitting the TRE-340 in tank.  It was a bit of a mission since the opening of the fuel tank is very small and the TRE pump was quite bit bigger than the original transfer pump.  Took a while to come up with a bracket design that I can get into the fuel tank.

After many iterations, I've come up with a bracket design that is able to clamp the pump into the factory fitting.  Photo below is is not of the final design - I'll keep that secret for now

To power the pump I ran some higher gauge wiring from the external pump to the new in tank pump.  The original wiring that powered the transfer pump is too thin and isn't suitable for running 6A.  Secondly, I discovered that the original transfer pump is only powered when cranking anyway, so it would never have worked without running the extra wiring.

I also replaced the fuel line with a smaller diameter one rated for 50 PSI.  To fit it, I turned a custom brass reducer so I can join that to the factory nipple.

Definitely took longer that I thought, but happy that its all working good now   Feel free to PM me if you're looking to do the same on your e30.

Edited January 18, 2021 by curryinahurry