hey guys i have a question... when i bought my 87 rx7 na my fuel guage worked but was off like it would say empty and i put $5 of gass in and would say full... then i changed the cluster and now it dont work at all i could fill it up and dont work at all... any sugestions?

 

Probably sender unit in the tank for the first part. After the gauge swap, no telling, lol...

 

check the FSM. It has some walkthroughs on how to test the impedence on the fuel level sensor unit and the gauge also. It helped my problem out. Similar, but not like yours.