-Is the Water Thermo Sensor basically your Water Temp. guage?
-If so, what does the Water Temperature Switch do?
-What does the variable resistor do? All I've found is it is used for a:f mixture adjustments. What if my variable resistor is filled up with some sort of glue? I've seen one where you can see down there and you can adjust it with a screwdriver, but mines wierd.

 

No. The Water Thermo Sensor is the sensor the ECU uses to determine engine temperature. The sender for the dash gauge is located under the oil filter.

Tells the ECU to use the 3K startup when the engine is cold.

Adjusts the A:F ratio at idle.

Good. Means you can't mess with it. There is almost never a reason to touch the variable resistor.

 

So a voltage is sent to the ECU, then the ECU checks a lookup table in the PROM and outputs it to the Sender? What's the sender?

Good to know, Thank you.

 

Sensor = sender. The ECU reads the temp from the temp sensor in the form of resistance, and uses this information to adjust the fuel curve.

 

So is this the water temp sensor that the "water temp gauge" in the dash reads from?


And the Water temp sensor that's on the front of the engine is the one that the ECU uses to tell engine temp?
And the water temp switch is the one that the ECU uses to decide on the Accelerated 3K Warm Up?

How does the computer know when to use the cold start assist? Is it tied in with these sensors?

Is there any documentation that goes over the ECU on FC's? Particularily an '86 'N326' ECU? Not wiring diagrams, but explanations.

 

you circled the oil pressure sender.

 

it is right above where you circled.The water sensor is 2 inches above rear trailing plug, and 3 inches toward the back of the car only has one wire with a funky connector on it I think it is the light colored wire in the top of the picture.

 

That water hose that is saturated in oil residue is going to *rot* and burst on you someday and all the water in the engine is going to fry.

The water temp sensor should be located one inch fwd of the hole for the oil temp sensor in the picture.

Download the series five FSM and read the descriptions in the FUEL SECTION. They are similar to the series four.

The Water temp sensor at the bottom of the radiator on a series four controls the 3000rpm for 17seconds upon start up but also effects the emissions solenoids like the Relief Solenoid which in turn effects the ACV.

Other things effect the 3000 startup like the position of the clutch pedal position. The fsm describes the temp that the water temp switch opens/shuts. Fuel section.