legacycentral bbs

My 93 LS won't start when air temp is 30F and is very hard to start below 50F. Also radiator fans come on immediately. Starts/runs fine in warm weather or on restarts if engine is still somewhat warm.

Classic problem is temp sensor. However Temp gage seems to reads correctly. Is this possible with a bad temp sensor ?

I understand the engine coolant temp sensor feeds both the dashboard temp gage and the engine computer which in turns controls the radiator fans,

I pulled coolant temp sensor.
Measured the resistance – 32F =4650 ohms, 65F = 2207, 200F = 440
Pulled coolant sensor from a different Legacy.
Measured the resistance – 32F =4450 ohms, 65F = 2510, 200F = 440
Bought a coolant sensor from AutoZone (only source open)
Measured the resistance – 32F =4360 ohms, 65F = 2468, 200F = 390
Basically no difference.

Chilton's manual (#8259 pg 2-34) spec lists: 212F = 26-29 ohms
This is 1/10th what I measure for all 3 sensors at 200F.

Is Chilton's spec wrong or do I have 3 bad sensors ?

How can I diagnose/fix this starting problem ?

Temp gauges on our cars are umm...kind of like the fuel gauges only better (they don't lie nearly as often).

Clean up all your electrical connections (like those between battery, starter and grounds). That probably seems irrelevant, but perhaps the cold weather is causing the metal to decrease in size somewhat and is causing bad connection. (Does it just crank forever or does it just click?) Might be a going starter as well...

Turns over very well - has a new battery.
When merely cool, have been able to get it started by putting the gas pedal to floor and cranking 10 secs. Then lifting pedal (idle position) and re-starting. Can take several cycles as it will try to start and die. When it does finally start ir runs rough until I can get the RPMs up to 2/3000 range. Runs fine as soon as it warms up. Acts like a choke problem if it had a carb.

Radio squeals a lot - OK for several minutes then squeals for several seconds. Only other problem I am aware of and probably not related to starting problem.

replace your coolant temp sensor. The gauge and ECU use different sensors. The temp sensor may read ok, but it's still bad.

They're about 20 bucks, www.subarugenuineparts.com , just replace it.