what is the sensor that is to the right (looking in from the right side of a 88 civic (D1B2 engine)) of the coolant temperature sensor.
according to my manual, the coolant temp sensor is in the back side of the block (under the distributor). if only has 1 wire (that one i have identified).
what is the one with 2 wires that is a few inches to the right of the coolant temperature sensor.

 

I have a 94 Civic LX (D15B7) and there are also two sensors next to each other. One is an ECT, the PCM uses it in fuel calculations. The other is a temp sending unit. It is hooked up to your dash to tell you how hot the engine is. Thats how it is on my car, and if both sensors are going into the block then I would guess thats the same for your car.

 

Yes both are measuring coolant temperature. The one closer to the front of the car, with two wires, is connected to the ECU. It is called the "coolant temperature sensor." The one nearer the back with one wire drives the temperature gauge on the dash. It is the "coolant temperature sender." There is even another sensor, the "coolant temperature switch" which turns the radiator fan on when the engine is getting too hot. On '91 and earlier models this switch is on the back of the engine near the oil filter (the one with 2 wires, the one with 1 wire is the oil pressure switch controlling the "oil" light on the dash). On later models it is on the thermostat housing.

 

i am lost on this one; as i recall from a bumbed up sensor a couple of years ago, the 2 wire sensor controlled the guage (i know that is not how you or Agent or Hayes has it).
but maybe what i did then was just coincidental.
i need to take the dis off tomorrow (or soon) and will be able to get into those sensors then.
thanxs to both for the reply