E30 fuel tank cleaning rusts

[Arata 28]

Hey team. My 325i died on Friday night (some people might have seen me at Pak n Save getting towed haha).

Did quick diagnostics while I was waiting for tow truck to come. Cranking forever and not starting. Funny enough I’ve already replaced fuel pump and fuel pressure regulator and other normal maintenance items so I’ve scratching my head. Got it towed back home, yesterday morning I’ve checked the usual things as it follows…

All relays working. Fuse and relay for fuel pump is getting power while cranking as well as at connector end. 
I added direct power to the pump and I can hear the pump moving.

Checked the fuel filter and it wasn’t the dirtiest as I’ve replaced about 1 year ago. But did some rust came out.

So put everything connected again and disconnected the fuel hose to the regulator and injector rail, fuel not getting to the engine.

So took out the pump again and this time I dipped in the fuel in the bucket and added the power directly, the pump motor moved but guess what, it’s back flowing from where inlet supposed to suck in the fuel to the outlet, this point I believe the fuel pump is damaged somewhat and I think bit of rust in the tank is the problem. I’ve already ordered the pump so hopefully I can at least test to see if anything else is the issue but meantime just wanted to see how you clean the tank inside. Any suggestions welcome. Thanks team.

[KwS 2373]

If the tank is real rusty, the best idea is to get it cleaned out and coated. I believe radiator shops can do this, pay to have a ring around.

Have a look into the tank and see how bad it is, if its not that bad you might get away with something like Evaporust.

[str8_6 270]

Just went through this saga with the e30 and decided a new tank was easier. 
Aftermarket fuel tank sourced from https://www.schmiedmann.com/ did the trick. Arrived in just over a week. Replaced the fuel pump and filter whilst in there. 

It’s also recommended to clean the fuel injector screens, or replace. 

Car is running like clockwork again. 

[Jono51 57]

The Fuel tank  from Schmeidmann is aftermarket , whilst a cheaper Taiwanese option, there are some differences, of which You'll see in my video

 

 

https://www.youtube.com/watch?v=scgunHwI7Rg

one thing I don't cover  in this video, is the filler neck may foul on the subframe and will need an "adjustment"  of sorts

 

If you need injector overhaul kits I've got them here 

Edited March 25 by Jono51

[Arata 28]

Thanks guys for suggestions. I’ll have a decent look inside the tank and decide what I can do. 

[Arata 28]

Update guys.

Managed to encourage myself to take the tank out and cleaned it during Easter holidays. The rust wasn’t as bad as I thought. Definitely needs another good cleaning with soaking in the solution but it came out much better. 
 

I used CRC Evaporust with distilled cleaning vinegar and was a good success of cleaning. I just had to keep rinsing and cleaning with acetone about 5 times fully till all rusts are gone. The photo of the bucket with rust was about the third time when I drained the tank.
 

Also at the same time, I’ve replaced the flexi disc on driveshaft as i didn’t notice that it was far beyond cracking. Don’t ask how I’ve been driving with it like that condition for the whole time… 

[APT 179]

That looks really good. How much evaporust did you go through ?

I'm looking at doing something similar on a E30 project I'm working on. 

 

[Arata 28]

22 hours ago, APT said:

That looks really good. How much evaporust did you go through ?

I'm looking at doing something similar on a E30 project I'm working on. 

 

I put 50/50 ratio and about 10 litres each. Soaked inside for 4-6 hours, and flip the tank upside down and soak further 4-6 hours.