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Path: utzoo!watmath!clyde!burl!ulysses!mhuxj!ihnp4!zehntel!jackh
From: jackh@zehntel.UUCP (jack hagerty)
Newsgroups: net.auto
Subject: Re: Logarithmic fuel gauges...
Message-ID: <1659@zehntel.UUCP>
Date: Mon, 5-Nov-84 20:06:20 EST
Article-I.D.: zehntel.1659
Posted: Mon Nov  5 20:06:20 1984
Date-Received: Wed, 7-Nov-84 08:11:38 EST
References: <232@scgvaxd.UUCP>
Distribution: net
Organization: Zehntel Automation Systems Inc, Walnut Creek CA
Lines: 20

> My '79 RX-7 has a really annoying problem with the fuel gauge.
> The damn thing reads F when I fill the car up.  Then, the speed
> at which the needle moves seems to change as the fuel level
> changes.
>                           ...this means the needle moves very little
> down at the bottom of the gauge and makes it impossible to get
> any idea just how much gas there really is in the tank.  

It's just possible that the Nichrome wire on the tank sender is wound
backwards.  These are usually wound logarithmically with the sparse 
end near full (so that a relatively large movement of the float is
required for a certian resistance change) and the dense end near empty
(for large resistance changes with float movement).

If this were installed backwards it would have the characteristics you
describe.

                                   Jack Hagerty, Zehntle Inc.
                                    ...!ihnp4!zehntel!jackh