86IROC112

Finally got the car running good enough to drive every day so I decided to fill her up. with the tank full the gauge only goes up to the 1/4 mark. Once the gas level falls below 1/4 it shows that but when filled beyond it stops at 1/4.

What are the possible causes of this? Does the sender have external wires like you find on an RV or am I screwed and have to drop the tank?

Vader

The '86 has the typical older style 90Ω potentiometer in the tank for a sending element. The sender should present a resistance to ground of 0Ω when the tank is empty and 90Ω when the tank is full.

Probably the easiest method to determine if the problem is with the sender or the instrument is to ground the pink wire to the sender. With the wire grounded the instrument should move to the empty position. Removing the pink wire from the sending unit should cause the instrument to move to the full position, and probably slightly above that. If that occurs the instrument is probably intact. If not, the sender itself or the wiring to it are suspect.

86IROC112

Is it possible to remove the pink wire from the sending unit without removing or dropping the tank?

John in RI

iTrader: (167)

With an 86 you could disconnect the tank wiring connector. The Tank wiring passes thru the body behind the upper rear seat cushion. To unplug it you need to get under the car and unplug the sending unit connector from the plug that passes thru the body.