Subject: Re: water into efi system before injectors.

[Mike (Perth, Western Australia)]

At 09:18 AM 19/3/2000 -0500, you wrote:
>I have a manual on the dual fuel 90-91 lumina, seems it had some sort of
sensor on the fuel line to determine the percentage of alchohol in the
fuel. any idea how it would work?

COuld be a straightforward conductivity sensor, as alcohol conducts 
electricity quite well and petrol is for the most part an insulator...
That would be the cheapest with minor drawbacks.

A simple 2v ac signal (to reduce change of electrolysis) into a bridge,
as the conductivity changes so does the 'indication' of alcohol in the
fuel - this is based on an assumption there's no water in the petrol
or in the alcohol for that matter...

(I say 2v - because thats easy to generate as the output of a pair of
gates from a LS ttl circuit through a pair of caps)

But can be quite effective if you do switch between alcohol and water
as the alcohol would sweep any water away and would therefore be good
for some consistency next time you change fuels etc

----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org