Gas Gauge Wrong

[AK49BWL]

Popping the needle off can work with stepper-motor gauges. Not sure how well it works with the older style balanced-coil gauge design.

Works the same way on either.

 

[Frank Enstein]

It has been my experience that the float arm is too short. I hook an ohm meter to the sending unit and eyeball it to get the length and bends right to get 90 ohms full and 0 ohms just before it hits the bottom. I did this on my wife's square body dually and her Astro van. It made installing the sending unit a M&^%&*%$*&&*er but it reads accurately. I have also heard rumors that GM made it read high for the top half of the tank so the customer thought they were getting better fuel mileage than what was real.

Also under 1/4 tank the fuel pump works much harder because it has to pull the fuel in. They like to push but not to suck.

 

[HotWheelsBurban]

It has been my experience that the float arm is too short. I hook an ohm meter to the sending unit and eyeball it to get the length and bends right to get 90 ohms full and 0 ohms just before it hits the bottom. I did this on my wife's square body dually and her Astro van. It made installing the sending unit a M&^%&*%$*&&*er but it reads accurately. I have also heard rumors that GM made it read high for the top half of the tank so the customer thought they were getting better fuel mileage than what was real.

Also under 1/4 tank the fuel pump works much harder because it has to pull the fuel in. They like to push but not to suck.

I would believe those rumors! Every GM vehicle we ever had was that way until the 99 Burbs. 5 different square Burbs, 3 square body GMC pickups, a Buick estate wagon and an 81 Monte Carlo. We used to go to DFW a lot, and it always would seem like we could go a lot further on the gas than we actually could. Once you got to half tank,seemed like it was more accurate.