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Fuel Gauge Bounces ......

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George Zeck

George Zeck

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Hi All -

My fuel gauge has always (since I got the car) bounced incredibly after I reach 50% full. Does anyone have some experience with the following voltage stablizer:

https://www.spiyda.com/magento/index.php/vehicle-electronics/instrument-voltage-stabilizer-kit.html

By the way, please be assured, the bounce I am seeing (again, after 50% runs through), is extreme. It's not a sharp turn or stop. Once I hit that 50% mark it just bounces continuously making the "I'm all most empty" impossible to determine.

I've pulled the generator and have a one wire Delco Alt in there (with supposed built in volt stablizer). Volt gauge I have shows good readings (& not bouncy).

Fuel sender replaced in approx 03 & 05 (2X) - but again, it's always bounced regardless of the unit.

Gauge is Smith's "BF2300 / 02" (replaced at the same time, via ebay likely in 03).

I think that covers the main items. Thanks.
 
Try smooth roads, hides head.

No real clue. But checking all the elec connections would not hurt, how about the voltage coming off the sending unit in the tank??
 
George, bouncing gauges are typical for cars that have the "moving iron" (magnetic) gauges. They don't have a voltage stabilizer in the circuit and adding one will not help. They are easily identified by having a thin needle that "jumps" off empty to wherever the gas level is as soon as the key is turned to the run position. The later gauges after the mid 1960s work by heating a bimetallic strip. Their needles are fatter/wider and when you turn the key to the run position the needle slowly swings up from empty to the correct level. Unfortunately the early and later gauge systems work differently and you cannot mix parts from the early and late systems. The regulator you mentioned on the charging system is totally different and unrelated.

For a bouncing gauge, try cleaning all the connections as Jack suggested. Also, run a dedicated ground wire between the car's chassis and the fuel gauge mounting screw/stud. On the early gauges the gauge case MUST have a good ground for it to operate properly.
 
George, I'm not sure you are using the correct matched components. The Sprite Mk2 used the gauges and sending units that do not use as supplied originally a voltage regulator of the later Mk IV sprites. It is very important that the gauge unit matches the fuel sending unit to have any chance to work correctly. Normally, some bounce is to be expected, and it is best when all the parts are correct to read the fuel level when the car is stopped. Good luck, Scott in CA
 
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