I have a 1973 240z, installed new gas tank and fuel sending unit. When I fill the tank full the dash fuel gauge reads full. After driving for about 100 miles the fuel gauge show 1/2 full. When I fill up the tank only down about 4 gallons. Any help will be appreciated!

2 minutes ago, yippi427 said:

I have a 1973 240z, installed new gas tank and fuel sending unit. When I fill the tank full the dash fuel gauge reads full. After driving for about 100 miles the fuel gauge show 1/2 full. When I fill up the tank only down about 4 gallons. Any help will be appreciated!

A lot has to do due with shape of a 240z fuel tank.  The top of the tank on the passenger side is higher and that is where the

sender resides.  The majority of the 15.9 gallons is contained in the lower half of the tank.  This may make sense once you

look at the tank and location of the sender.

Thanks for the response, I have fill up each time when the gauge is reading 1/2 tank and each time it took the same amount of fuel. I will continue to drive the 240z pass the 1/2 mark and check to see if the needle on the gauge slow down.