C1 Gas gauge calibration

[David H.]

On my 1961 Vette the gas gauge was off so I removed the sending unit and calibrated it to 0 and 30 ohms.
Adjusted the float also to be at the bottom of the tank when empty.
Seems accurate except when empty the gauge reads just slightly above the empty line.
By adjusting the tab on the empty side of the float stop, will that correct this?

[Frank D.]

Re: C1 Gas gauge calibration

On my 1961 Vette the gas gauge was off so I removed the sending unit and calibrated it to 0 and 30 ohms.
Adjusted the float also to be at the bottom of the tank when empty.
Seems accurate except when empty the gauge reads just slightly above the empty line.
By adjusting the tab on the empty side of the float stop, will that correct this?

If you've gotten your gauge that close then its better than 98% of the cars out there and far better than the factory setup - personally I'd leave it alone. Are you really gonna run your classic Corvette to the point of an empty gas tank -- or even close ?

[Richard M.]

Re: C1 Gas gauge calibration

I agree with Frank. My '59 gauge shows 1/8 of a tank when I've run out of gas. I always keep filling when I get to 1/4 tank reading on the gauge.

Internally, the wirewound resistor wiper contact is at it maximum travel at the tab stops. A EMPTY reading is Zero ohms, so you cannot get any lower than that with a mechanical adjustment if you are reading that now.

Bad sender in the photo but shows the internals.

P3140001.jpg

[Brian T.]

Re: C1 Gas gauge calibration

The only way that it can be corrected at this point would be a calibration to the dash gauge which is achieved by movement of the coils.

[Richard M.]

Re: C1 Gas gauge calibration

The only way that it can be corrected at this point would be a calibration to the dash gauge which is achieved by movement of the coils.

Brian, Could you hold the needle base and slightly bend the needle CCW?

[Brian T.]

Re: C1 Gas gauge calibration

Rich, yes you could do that, but keep in mind, it will make it read a little lower on the full side.

[Richard M.]

Re: C1 Gas gauge calibration

Rich, yes you could do that, but keep in mind, it will make it read a little lower on the full side.

Thanks Brian.....Good point, I didn't think of that.

Rich

[Brian T.]

Re: C1 Gas gauge calibration

Any time Rich. The correct way is to calibrate with the pointers. Usually if a slight bend on the needle makes it right at high and low points, it is because it was already tweaked! I often see the gauges read a bit low on the high side when using a real 30 ohm test setup.