My notes from an '83 turbo rebuild show the Temp Sensor in the block, below the #4 intake position. It has a Gray wire. It is below the CIS (Constant Idle System) Temp Sensor, which has a Red wire and a Blue wire.

The Gray sensor wire goes through the 8-pin connector on the Left (driver's) side of the fire wall (pin 4. The Red Alt D+ wire is just above it). This connection or the wiring may be stopping the signal from getting to ECU pin 7.

I am surprised that this sensor signal is a problem for you in Guatamala. because it is only meant to signal a temperature below 60°F, so that the ECU will ignore the cold O2 sensor signal until some engine warming.

The "preset" Dwell (using 4 cylinder scale) with O2 sensor disconnected and ECU pin 7 grounded should be 68°. The normal (warm) dwell should be about 45° for turbo (55° for non-turbo)
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Bruce Young — Credo: "I tweak therefore I am"
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.