@Olaf i have a story that might make you laugh then haha
back in my e30 days when i was younger, one of the spare e30's i had was parked up for a long time, and water got into the fuel tank, alot of it, how, i dont know, but it wouldn't start because water was the only thing going through the fuel pump
we tried draining the fuel tank, but the design of the fuel bowl is that even after draining the fuel, the water remained right in the area that would get sucked up by the fuel pump
I didnt have any suction type things that could reach it either
But water is soluble in ethanol, so i poured like 5l of ethanol in, it dissolved all the water, and then poured the fuel in and just like that, the e30 was back in action.