Coolant Temperature Sensor - 1991 300ZX Z32

The Nissan 300ZX Z32 twin-turbo requires the specific 22630-44B10 coolant temperature sensor mounted on the driver-side cylinder head near the thermostat housing to maintain proper ECU control. When sourcing from junkyards, target any 1990-1996 Z32 chassis but verify you retrieve the 2-pin ECU sensor, not the single-wire gauge sender (25080-89907) mounted on the intake manifold. The 22630-44B10 calibration is specific to the VG30DETT; while the 22630-15U00 from naturally aspirated models threads in correctly, its resistance curve triggers incorrect fuel enrichment and retarded ignition timing under boost. Test used sensors by suspending in heated water: resistance should drop from approximately 2.5 kΩ at 68°F to roughly 300 ohms at 176°F. Installation requires a 19mm deep socket, thread sealant, and 15 N·m torque to prevent coolant leaks into the connector. Inspect the plastic connector for heat embrittlement—a common failure point causing intermittent open circuits and hard-starting complaints.