I recently bought my 1990 k5 and after driving past the half tank mark, it went to 0. What is the fix for this issue, it seems only half of the gas gauge works and I want to fix it.

 

Can you confirm that the tank was still about half-full when the gauge dropped from reading about 1/2 to empty? Does this happen regularly?

If the answer to these questions are all yes, then I would think the likely culprit is the sender unit in the tank.

 

Thanks