Re: '77 Spider Fuel Gauge

[jack@domain.elided (Jack Hagerty)]

>Kenneth M Tubman writes: 

>The fuel gauge on my '77 spider does not read accurately.
>It never reads full, and often reads dead empty, even when
>there is plenty of fuel in the tank...
>I replaced the sending unit with a used one from APE, but
>I still have similar behavior. How do I check the sending
>unit and gauge?

I've seen the standard reply show up (i.e. to check the grounding
of the tank), but it doesn't sound like that's the problem in this case. 
I'm presuming that the "never shows full/shows empty with gas left" 
is the only symptom. The needle is steady (doesn't jump around) and 
works smoothly between the two extremes.

If that's the case, then your sender is in backwards. I don't know
if it's the slope of the tank in the car or what, but the float hangs
differently depending on which way it's put in the tank. If it's put
in backwards, there's a bias towards empty meaning, just like you
describe, the gauge will have a head start towards empty even with
the tank full, and will get to empty before the tank does.

To fix it, just remove the float, roatate it 180 degrees and re-install.

- - Jack

+---------------------------------------------------------------------------+
| Jack Hagerty                |    "If this rocket stuff is so important    |
| Robotic Midwives, Ltd.      |    to you, so be it. Just be careful and    |
| Livermore, CA		      |    don't blow yourself up. I suppose there  |
| jack@domain.elided   |    are worse hobbies!"                      |
| (925) 455-1143 (voice/fax)  |            - John Hickam, October Sky       |
+---------------------------------------------------------------------------+
|        ARA #97, NAR #55105, LUNAR #002 / TRA #3943, Aero-PAC #168         |
+---------------------------------------------------------------------------+

------------------------------