Need Help with fuel guage.. :(

OK...a 1976 PA 28 151..

After a few minutes of running, the port guage will start to fall
towards E.

It is showing 3/4 now (fuel at tabs), and will sag to 1/4 within
about 15 min, while I am operating on the starboard (other) tank.

Shut down for a few hours, guage resumes normal (correct) indication.

We have checked / replaced, tank grounds, sender, wiring to guage.

I think the guage terminals handle 12 V to the left terminal
(looking at it from under the panel) (starboard terminal) , The other
to the tank sender (port terminal).. (grounding this terminal when
the fault is present will cause a "full" indication).

From what I recall, there is a "ground" connection internal in the
guage. Anybody know how this is grounded?

I suspect a bad connection here somewhere..

Driving me up the wall..of course every time I attack the problem,
meter in hand, it works fine.

Anybody any ideas? Suggestions or test procedures?

Dave

"Dave" wrote in message
...
OK...a 1976 PA 28 151..


Anybody any ideas? Suggestions or test procedures?

Dave

Try swapping the meters (fuel guages) in the panel. By that I mean switch
the wires, so the left guage is wired up to the right tank. See if the
problem moves or stays.

Tank venting.



"Michael Ware" wrote in message
...
| "Dave" wrote in message
| ...
| OK...a 1976 PA 28 151..
|
|
| Anybody any ideas? Suggestions or test procedures?
|
| Dave
|
| Try swapping the meters (fuel guages) in the panel. By
that I mean switch
| the wires, so the left guage is wired up to the right
tank. See if the
| problem moves or stays.
|
|

Must be made by Belfort Instruments!! ;-)



In article ,
says...


OK...a 1976 PA 28 151..

After a few minutes of running, the port guage will start to fall
towards E.

It is showing 3/4 now (fuel at tabs), and will sag to 1/4 within
about 15 min, while I am operating on the starboard (other) tank.

Shut down for a few hours, guage resumes normal (correct) indication.

We have checked / replaced, tank grounds, sender, wiring to guage.

I think the guage terminals handle 12 V to the left terminal
(looking at it from under the panel) (starboard terminal) , The other
to the tank sender (port terminal).. (grounding this terminal when
the fault is present will cause a "full" indication).

From what I recall, there is a "ground" connection internal in the
guage. Anybody know how this is grounded?

I suspect a bad connection here somewhere..

Driving me up the wall..of course every time I attack the problem,
meter in hand, it works fine.

Anybody any ideas? Suggestions or test procedures?

Dave

Jim Macklin wrote:
Tank venting.

I assume he actually sticked the tanks to verify there was
fuel, it's not a cessna.

If the vents are partials plugged, the fuel can siphon tank
to tank and also may feed asymmetrically. Also, it can be
pushed from a tank to another by trapped pressure as the
plane climbs. Also, if the plane is not truly trimmed, g
forces can push fuel just like it pushes the "ball."


--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.


"Ron Natalie" wrote in message
m...
| Jim Macklin wrote:
| Tank venting.
|
| I assume he actually sticked the tanks to verify there was
| fuel, it's not a cessna.

Thanks all....

...... but note in my post, the sender has been replaced with new, the
rsistance is exactly on spec, and no dead spots in it's operation..

The fuel level has no effect on the fault..the guage literally "goes
to sleep" when ever it feels like it, usually after about 15 mins,
then occassionally, during flight, "wakes up" and reads correctly for
a few minutes.. then away it goes.. (down)..

Switching wires to the guages is a bear of a job under the panel, but
I may do it back under the seat, just to be sure..

Anybody know where to get a wiring diagram/component location info on
the Warrior? my CD manual is a bit lacking here...

Dave






Thu, 02 Mar 2006 18:27:17 -0500, Ron Natalie wrote:

Jim Macklin wrote:
Tank venting.

I assume he actually sticked the tanks to verify there was
fuel, it's not a cessna.