Diesel Fuel Tank Removal

[Neukirchen]

I’m Looking into fuel tank removal, for cleaning purposes. This ‘85 diesel golf has sat for 6 years, is ready for the road again, but - before I fill it up and change the fuel filter- I’d like to ensure the tank and fuel lines are clean.

Please tell me what you have done/do/would do in my shoes.
Thank you! M Neukirchen, Eugene, Oregon, USA

[sgnimj96]

Be prepared to clean more than just the tank. Might have to fix some body rust

If nothing has moved for 6 years, that fuel pump and the injectors may be stuck inside with old fuel gunk.
That's another topic.

Is that a plastic tank?.

[Fatmobile]

For cleaning out a tank,
I use an electric fuel pump with a filter in front of it.
It sucks up all the crap in the tank, filters it, then runs back into the tank to rinse it out.

Kind of like vacuuming the tank but with liquid.
Congrats on finding a MK2 golf to work on.
I think the '85 golf is the only MK2 built with a manual steering rack.
It also has the rare grill with rectangular headlights, so don't hit a dear.

[Neukirchen]

Thanks for the replies! I emptied the tank by siphoning (couldn’t find my spare fuel pump, but will keep looking!) and filtered it before putting it back. The fuel lines pass clean fuel through, though there may yet be plaque to flush out. I think I’m ready for the fresh fuel filter - although the old filter appears clean, with no visible particulates or obstruction to flow. I have a small vacuum gauge to install - between the injector pump and filter- but still need to find a “T” fitting for installing that; do you use one of these gauges? I understand they’re fairly standard on the big rigs.
I started by rebuilding the injector pump, injectors and rebalancing the injectors to 135 +\~ 5psi, I purchased a pop tester off of eBay, and had to make my own injector shims by polishing down some steel washers. This made the spray pattern, from the injectors, a perfect puff of vapor - like a cloud. The car starts easily now.
I had to dismantle the pump as it was not putting anything out. The problem appears to have been 2 sticking vanes on the feed pump. They couldn’t do their thing due to scuffing of the metal around the channel that holds them, way at the back of the pump. I took care of this with a small file so they could slide in and out easily.
If you want any more details, feel free to ask.
Thanx again! - Michael

[Fatmobile]

Yes, all my 1.6 diesels have a dash-mounted vacuum gauge connected to the front of the pump.
The old gasser Rabbits had a double-stacked banjo bolt that makes it look like a clean install,
no clamps.
Sometimes I tap the banjo bolt, 1/8" NPT, and screw a small barbed fitting into it.

[sgnimj96]

I like to use these cheap mercedes filters as a pre-filter (strainer) before
the main fuel filter. Nice to see whats coming out of the tank.
If they get clogged up it's easy to remove it, clean it out backwards,
and put it back on.
https://www.rockauto.com/en/moreinfo.ph ... GWU9npNisE

[Neukirchen]

Be prepared to clean more than just the tank. Might have to fix some body rust

If nothing has moved for 6 years, that fuel pump and the injectors may be stuck inside with old fuel gunk.
That's another topic.

Is that a plastic tank?.

Thanks for the reply! I assume it’s plastic, since the magnet doesn’t stick to it. The tank appears to be held in place with a couple straps.
I cleaned the tank by swabbing the bottom of it with a rag, and then sucked out the fuel through the access hole .
I then filtered the fuel, put it back in and installed the new filter.

[sgnimj96]

biocides are good to use every once in a while, especially for fuel jugs that sit.
Stuff the truckers use will last a long time with vw-sized doses.
The one I have is call biobor JF.

[Fatmobile]

That's a great point.
Fuel that has sat for awhile, with condensation adding water too it
will breed bacteria.
Even if you clean the tank, the seed for more bacterial growth will still be there.