temp sensors?

[datsunson]

77 a/t 280z

there are 3 sensors on the upper radiator neck. one has a male bullet connector and the other 2 have clips with 2 wires going in to each. what are each of these sensors for? particularly the one that needs a 25mm socket

[sblake01]

The one with the bullet connector is the thermal transmitter. It's for your water temperature gauge. The other two are fuel injection system compononts. The smaller of the two is the water temperature sensor. The other is the thermotime switch.

The water temperature sensor is a thermister. It begins with a higher resistance when the engine is cold and decreases the resistance was the coolant temp rises. It changes the fuel enrichment and fuel injection pulse as the engine warms up.

The thermotime switch has a coil inside that begins to heat up when it gets a signal from the starter and sends it to the cold start valve, but only when the coolant temperature is below 35 deg. C. and will only operate for a maximum of 8 seconds at which point the cold start valve will close.

[datsunson]

thanks again. you wouldn't happen to know a place to get a thermotime switch for a decent price and does the engine rotate clockwise or counter-clockwise looking at the front of the car?

[MEZZZ]

http://www.thezstore.com/page/TZS/PROD/SFC03G/11-3460

Motorsports Auto $64.32

There is also a guy on Ebay that always has one listed,

http://cgi.ebay.com/ebaymotors/_Car-Truck-Parts-Accessories__Datsun-280z-280zx-Thermotime-Switch-Washer-NOS_W0QQitemZ320283908487QQadnZCarQ20Q26Q20TruckQ20PartsQ20Q26Q20AccessoriesQQadiZ2865QQcmdZViewItem?hash=item320283908487&_trkparms=39%3A1%7C65%3A1%7C240%3A1318&_trksid=p4506.c0.m245

Not sure what his reserve is, Ive bid on several items and never hit the reserve, he seems very proud of his items.