I've noticed that my FC consistantly displays Incorrect readings. When I fill up, like to the neck of the fuel tank opening, my gauge reads 3/4 full! But when I'm low on gas my gas light and readings are correct. What gives? Is the float in the gas tank suspect?

Everything works on my 88 GXL. No rattles, electrical bugs or rust. It bothers me that the readings are out of whack! What could be causing this?

 

Come on, nobody. I'm sure somebody knows.

 

Just a bad sending unit in the tank. Been there, done that. Wreck yard . The online manual gives you some values to check but its most likely the float unit in the tank. Pumps attached to the same structure. Mine would show three quarter at full and after maybe a hundred miles drop to zip. Swapped with my other car and all was well. Went junk yard. Maybe ten bucks wo the pump.

 

So If I get one from the dealership, what do I ask for? Fuel float sending unit? Also the FSM makes no reference, let alone a picture, to the sending unit

 

You will need the sending unit assy. Mazdatrix has new assy for $72.