All posts for the month April, 2022

The EFI system components are installed and wired in.

All that remains is to put gas in the tank and fire it up. But before putting gas in the tank there has to be a way of determining how much gas there is in the tank. Fuel in the tank is measured by a sending unit comprising a float attached to a variable resistor that is sealed in the tank. The amount of fuel floats the float, which changes the resistance. The resistance is wired to the fuel gauge on the dashboard, which measures the resistance to indicate the amount of fuel.

The sending unit in the my tank wasn’t varying the resistance (i.e., it was broken), so the sending unit had to be replaced. As with any old car, parts are sometimes difficult to obtain. Although there was a replacement part listed in several catalogs, the part was nearly always out-of-stock/unavailable.

Another consideration is that the resistance range of the sender has to match the range of the gauge. Although I eventually found an in-stock sender I was not able to determine what the resistance range was prior to purchase, so I’ll have to wait until the part arrives and measure the range. If the range doesn’t match my gauge I’ll have to find and purchase a gauge that matches the sender. This is why working on old cars can be a pain in the ass, costing time and money.

Kudos to Pat Wilson’s T-bird Parts for their fabulous customer service!  Thanks, guys!


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