Finally got some resolution to the NIKKI fuel pump dilemma.
I received a new pump with the components to rebuild my old NIKKI, this all worked fine until I put it in the car. The pump did not work.
I eventually found that I was not getting any fuel from the fuel tank. I blew compressed air into the fuel lines to no avail.
When I bought the car I removed all the old fuel about 25 litres and replaced this with fresh fuel.
With no real answers I eventually succumbed to removing the tank. Emptying the tank I found the fresh petrol was black then orange. I managed to get out about 25 litres.
On removing the tank straps I found that there was even more fuel in the tank, another 25 litres.
The fuel was saturated with black tar like substance and orange looking crystals a bit like sugar.
A little reading and apparently this is what happens to old fuel.
I also read that caustic soda in hot water breaks down this substance at a molecular level. I also read that the mechanical breakdown of the really hard material in the bottom of the tank could be achieved by placing old chain and off cuts of steel and old bolts into the tank and shacking it about. What I found was that there was a thick layer of black to orange material in the bottom of the tank subsequently blocking the fuel pickup pipe.
About 7 hours later and at least three soakings with Caustic soda in hot water and much shacking about I managed to finally obtain free flow through the fuel pickup. Yes it nearly killed me.
With this all apart I now have a painted tank and straps and new fuel lines and breather hoses installed.
For the final clean I left the tank out in the sun over the weekend to dry out and found more orange material loose in the tank, so I placed the chain back in the tank dry and chock it all about to loosen any other material. Once happy I removed all the loose material.
The tank is now back in the car and today after 32 years the car started. Sounds wonderful.
The attached photos show a sample of what I removed from the fuel tank. The orange material is not rust its old fuel.
I hope this helps others with cars that have sat around for a long time to sort out their fuel pump problems.