FUEL TEMP SENSOR FAULT

[rgregoryb]

OK Z32 Brain trust
My ecu gives me a code 42, fuel temp sensor, so far I have replaced the sensor, replaced the connector, checked the wire from the sensor to the ecu and it is good no breaks. I have also cleaned the ground wires for the fuel rail. Erased the codes on the ecu, drive the car (runs great) and still get a code 42 when checking the ECU.

1. The only other possibility is the ECU?

2. Does the car even need the fuel temp sensor because it is only used during initial start up, or do I misunderstand it's actual function?

[rgregoryb]

Geez, I hoped for a genius to step in. So I started looking harder and could not really tell if the fuel rail was really grounded. Well, it wasn't so I put a washer with a wire soldered to it and put the sensor through it and tightened the sensor then connected the other end to a ground point. Ran ECU codes and got 55.

[itsa300zx]

Hmmmm, must have missed this post. The fuel rail is grounded via a braided ground strap the bolts to the lower plenum, near cylinder 6.

[rgregoryb]

Kind of hard to get to without removing plenum, so I made my own ground.