Dodgy fuel gauge?

[paps78]

My fuel gauge has a mind of its own. when i first start the car it often stays at full even though they maybe a half tank.It does drop down after i tap it a few times. Recently its taken to fluctuating intermittently. any ideas whats wrong and how to fix this. any thoughts greatly appreciated

[Cabri-Ole]

Mine too? I recently replaced the SI board and now on start up my fuel guage reads full then drops back to the correct reading after a few minutes. It didn't do this before the new SI board??? Don't know if connected or something wrong at fuel tank end? Help....

[tez180]

check your nuts

[Cabri-Ole]

On the back of the instrument cluster? Why is this? Thanks

[tomo9992]

mine flicks constantly all over the place like lightenin, never reads actual fuel level, any ideas why on that 1?

[tez180]

Yes on the reverse of the cluster.

[Cabri-Ole]

Thanks Tez
Come to think of it i've an idea there was no nut on the thread comin thru from the fuel guage (like there was on the temp guage!!!) Back out with the instrument cluster again