Vauxhall Zafira A - Fluctuating fuel gauge | HELLA

If there are complaints for these vehicles that the tank gauge does not display "Full" (4/4), [instead displays approx. 3/4] even though the tank is full, a possible cause could be that the fuel pump assembly is not correctly aligned in the fuel tank.

Cause:

The fuel supply assembly/swirl pot of the fill level sensor may have been incorrectly installed or not properly engaged.

In this case, check the alignment of the fuel pump assembly and the connections/joints through the service opening on the fuel tank and correct them if necessary (firmly press down/engage the swirl pot).