Re: Verde stalling - Fuel problem

["Michael Liu" <mliu@domain.elided>]

> From: Bpnmrice@domain.elided
>
> > I'll suggest everyone avoid ARCO - I'm very sure I have water in my
> > gas thanks to a few fillups at ARCO.  Water comes out of the exhaust
> > on startup - and it's DRY here in California right now.
> ============
> Every car I ever owned had some amount of moisture (water) come
> out of the exhaust at start up. The water is a natural by-product of
> combustion. The main reason drivers are urged to drive at least 20
> minutes is so that the exhaust system can get hot enough to boil out
> all the water that accumulates (otherwise the dreaded muffler eater
> goes to work).

Bob hit the nail on the head, but allow me to elaborate. When you combust
gasoline, the hydrogen molecules from the gasoline combine with the oxygen
molecules (from the air) to form good 'ole H2O (AKA water). Therefore, a
large percentage of your exhaust is in fact water vapor (AKA steam). When
you first start your car, the steam in the exhaust gases hits the cold metal
of your exhaust piping and condenses into liquid water; this is what you
will sometimes see sputtering out of your tailpipe. Why are you seeing it
now versus other days? Most likely due to cooler outside temperatures and
perhaps a higher relative humidity. Warming up your car (and thus your
exhaust system) will not only boil off this condensate, but will also
prevent any more from occurring while the system is hot, which is why the
problem goes away with some driving. (Btw, water in your exhaust is bad
enough from a corrosion point of view. What's worse it that the water
combines with unburned nitrogen and sulfur compounds in the exhaust to form
nitric acids and sulfuric acids. That will really mess up your exhaust
plumbing!)

Another possibility here is a coolant leak into your exhaust, most typically
due to a blown head gasket or a warped head. Hopefully that's not the case!

I missed your original post (I'm new on this digest) so I'm not sure what
your symptoms are besides the water droplets from your exhaust. It seems
from the subject line that your engine running poorly. If there was enough
water in your fuel for it to be spitting out the tailpipe, it probably would
stall seriously, if not completely. (That is why aircraft pilots always
drain a little fuel from their tanks before flight to get rid of any trace
of water condensation in the tanks--you don't want your engine to quit at
5000 ft!) If you ever were to get a considerable amount of water in your
fuel, an additive is probably not the solution. Your best, and perhaps only,
recourse would be to drain and flush the entire fuel system (but not on the
ground). In any case, it's probably not fair to condemn ARCO as a whole. If
water did get in your fuel, it could have been a problem just at that
station. (Standard Disclaimer: I don't work for ARCO or have any interest in
the company. I don't even buy their gasoline.)


Michael Liu
San Francisco, CA
'90 Alfa Spider
'69 FIAT 124 Spider

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