Goodguys Preparation - Fuel Gauge Adjustment

Adjusting your sending unit so the fuel gauge shows right is not the most exciting task.  I'd much rather be putting on some new speed part, interior item, or just about anything else.  At the end of the day, the fuel gauge works better but otherwise, its hard to tell you did much and you stink of gas.

My fuel gauge was showing I had a little under a quarter a tank of gas then the tank was empty.  I was surprised to find that out driving down the road one day.  I've mentally adjusted but the fact it does not work right bothers me.  I decided to fix it so I know how much gas I have going to Goodguys in a few weeks.

In doing this task before, I knew I'd be draining the tank and testing it a few times to get it right.  To make it easier, I purchased an Edelmann draincock with a hose attachment (#308400) for this task. After draining the tank the first time, I put this in place of the drain plug which simplified draining the tank between tests without spilling as much on the garage floor.

After draining the fuel and installing the draincock, I pulled out the sending unit.  I laid it out on a piece of cardboard and marked the location of the float as a baseline.  This was to track the various adjustments to track progress and return to a previous setup if needed.  

I first checked and adjusted the sending unit so empty was 70 ohms and full was about 10 ohms.  After this was done, I started slightly bending the float arm to get the gauge to read exactly as I wanted.  It took five attempts to get the sending unit adjusted to the point I wanted.  My goal was to have about 2 gallons left when the gauge showed empty.  

The following pictures are more for my own person reference later.....

The gauge looks as follows when the tank is completely empty but with the ignition on...

With two gallons of gas...

Finally, with three gallons.  Ends up, at empty, I probably have just over two gallons...

I wondered if driving around with 3 gallons of fuel was possible without any problems (sputtering).  I drove around for a while up inclines and around numerous corners for over 10 miles.  I drove until I was at empty on the gauge.  Everything worked just right such that I can go to E without any concerns and trust the gauge.  I then filled up with gas and confirmed the gauge went to full.  

One more problem solved.  I'd like to get the following things done in the next month:

Change Oil (Fix Leak)
Front End Alignment
Adjust Parking Brake
Fix Coolant Leak