Fuel gauge goofy

[san dimas]

Hello everyone,
My fuel tank holds 23 gallons. I emptied it and my fuel gauge read 1/4 full. I added 10 gallons and it read full. This is obviously wrong. Is there an adjustment on the sending unit or gauge itself or what could the problem be? On the water the gauge drifts off of full as the boat moves side to side but not much. I hate trying to guess how much fuel I have left so I'd really like to fix it. Thanks.

 

[Scott Danforth]

Re: Fuel gauge goofy

if you want to fix it, you most likely will need to get a new fuel sender and fuel gauge.

 

[Bondo]

Re: Fuel gauge goofy

Hello everyone,
My fuel tank holds 23 gallons. I emptied it and my fuel gauge read 1/4 full. I added 10 gallons and it read full. This is obviously wrong. Is there an adjustment on the sending unit or gauge itself or what could the problem be? On the water the gauge drifts off of full as the boat moves side to side but not much. I hate trying to guess how much fuel I have left so I'd really like to fix it. Thanks.

Ayuh,.... There's a chance that the sender could be pulled, 'n the float arm bent, which may, or may not fix the level issue,...

The bounciness probably not,....

 

[wrench 3]

Re: Fuel gauge goofy

If the sender has been replaced before, most replacement units are adjustable for tank hight and float arm length. The gauges very seldom give problems. It's usually the wiring or the sender.

 

[jc55]

Re: Fuel gauge goofy

If you pull the sender out and raise the arm or float to the highest position, it should read full on the gauge. When you lower it to the lowest position, it should read empty. If it does not, you most likely have a bad sender or bad wire connection as mentioned. The sender is just a resistor and the gauge an ohm meter. You can check the resistance with a meter through the sender's stroke. Isn't GM a standard? I forget the value.

I bought a universal style at NAPA when mine went out on the Baja. I adjusted the arm to calibrate it by using a tape measure to measure the depth of the tank then compared that to arm swing using the mounting flange on the new sender as a point of reference. Double check the stroke using the gauge before install.

 

[tazrig]

Re: Fuel gauge goofy

Also check to make sure your sending unit AND gauge have the same range for their ohms ratings.

 

[san dimas]

Re: Fuel gauge goofy

Thank you all for your help. Great suggestions!