It is pretty messy in there, that's why im not keen on using any additives to dissolve it any further. My car sat unused for 5 years and developed that foul stale fuel smell. Additives may be good to maintain a tank so this doesn't happen, but this one needed a flush.
I have decided to put 2 of the Alfasud cheap plastic disposable type fuel filters after the pump, that way if the first one clogs up, i can quickly remove it and get the car going again before the traffic banks up too far. I am still traumatised by that feeling of the throttle going dead from fuel starvation on the overpass during peak hour traffic.
Alfasud mechanical fuel pumps need to be looked after as they are no longer available, but i think the pump should be able to pass small debris without any problems.
So i put a 3rd metal mesh filter before the pump, in the form of a modified Alfetta/105 style glass bowl type filter housing with a fine metal mesh instead of the paper element.
This mesh is much finer than the one on the pick up pipe in the tank so cleaning will be much easier in the engine bay as the tank wont need to be lowered.
See pic with ruler showing mesh in tank about 1mm and mesh before pump about 1/4mm, and pic showing metal mesh instead of paper element in the 105/alfetta filter housing.
The inlet fuel hose of the alfetta/105 filter is the same 5/16 diameter as the alfasud supply hose.
Last 2 pics show my new filtration system, 2 disposable filters after the pump and an alfetta/105 filter before the pump.
A new tank would be nice, as this is not the first Alfasud i have had that suffered from fuel starvation. So far i drove the car all day today with no problems, although with a full tank of fresh fuel.
driving: a twin carb