Watery fuel

[C M Smith <cmsmith@domain.elided>]

Talk to us Canadians about water in the fuel. Trust me, the water coming 
from your exhaust isn't necessarily coming from your fuel supplier. At 
least you shouldn't worry too much about water from the exhaust because 
your engine creates some water with every combustion event, regardless of 
whether your fuel was "dry" or not. Dirty fuel is a big problem, water is 
no problem.

We get water in our fuel every winter from the normal breathing of the fuel 
tank and the daily temperature cycling. In fact, if you get enough without 
dealing with it, you can sometimes hear the chunk of ice doinging in the 
fuel tank!!! Water sinks to the bottom of the tank. In Canada, the water 
can freeze in the fuel tank, causing no problems at all until it warms up. 
Modern FI being what it is this usually happens on a longish highway run as 
the hot surplus fuel gets dumped back into the tank, melts the ice, then 
the fuel pump sucks it up and either the engine dies from total fuel 
starvation or lurches and stumbles as it tries to digest the water as if it 
were fuel. Of course, this cools down the intake charge so you could get a 
burst of power too (yeah right).

Fuel driers contain alcohol, isopropyl is best, methanol is much more 
common. The neat thing about alcohol is it dissolves both in hydrocarbons 
such as gasoline and in water, the word "dipolar" rings a bell. Anyway, the 
alcohol acts as a solvent for the water and the combined gasoline, alcohol, 
water mix burns nicely in the engine, no stumbles no stalls.

All winter long I add a 125 mil bottle of methanol, or preferably isopropyl 
alcohol, to my fuel tank whenever the temperature fluctuates widely, say 
more than 10degrees Celsius. At least once per year I try to use a good 
name brand fuel injection cleaner as one of the main ingredients is a drier 
(probably isopropyl).

When the temperature drops to minus 30 degrees Celsius here the condensing 
water vapour from the tailpipes can actually be so thick you can't see 
through it at the traffic lights when everyone drives off!! This is just 
normal combustion water, not water in the fuel (that's frozen solid in the 
tank!)

Michael Smith
Calgary, Alberta
Canada
91 Alfa 164L, White, original owner

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