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Scott,
I don't think you're testing a coolant temp sensor. Your K-jet has only a single (Gray) wire Thermal Cutout Switch, which stays closed below 60°F to keep the Fuel Injection ECU in cold-running mode. This richer (fixed mixture) setting ignores the signal from the O2 sensor. Over 60°F, the TCS opens, signalling the ECU to control fuel mixture based on O2 sensor signal voltage.
A short to ground in either the switch (not likely) or its wire (more likely) would cause the ECU to stay in cold running mode, and probably result in high HC readings.
If the sensor you're testing has 2 flat-blade contact terminals, and is VDO (not Bosch), with Yellow/Blue and White wires, it's the Thermo-Time Switch. The one in my junk pile reads about 32 ohms at room temp, as you describe.
The B21 head/block sensors can be confusing. I made a sketch and notes from an '82 Turbo (K-jet), as follows (looking at the left side, under the intake runners and in the block):
° In Head, #2 intake runner: Below-left: Wax Thermo-valve (may not be there). Below-right: Inst. Gauge temp sensor (Yellow wire).
° In Head, #3 runner: Below-right: Thermo-Time Switch (described above)
° In Block: Below #4 runner (upper sensor): Coolant Temp Sensor for CIS (Idle Control) system. Two wires, Red and Blue. I doubt it relates to high HC test readings. Maybe the shakey idle though. At room temp it should be 2,100 to 2,900 ohms.
° In Block: Below#4 runner (lower sensor): Lambda Thermal Cutout Switch. This is your only FI temp "sensor". For cold-running, as decribed above.
Sorry if I went on too long. I'll watch for your progress,
PS - No "Engine Check" lights till 1989
--
Bruce Young,
'93 940-NA (current)
'80 GLE V8 (Sold 5/03)
'83 Turbo 245
'76 244 (lasted 255,000 miles)
73 142 (98K)
'71 144 (track modified--crusher bound)
New 144 from '67 to '78
Used '62 122 from '63 to '67
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