Checking the ECU’s Water Temperature Sensor:

David Balingit <[email protected]> writes:

There are two water temp sensors. One goes to the ECU and one goes to the temp gauge. The sensor with the F.I. type connector is the one you need to look at. (It’s the LEFT one of the 2- as you look over the radiator at the engine.)

I wish I had my manual in front of me, because then I could tell you the normal resistance vs. temperature. (Heheh! We’ll help ya’ out here Dave! :-) A&W)

Temperature Deg. F. Resistance k Ohms
2.1 - 2.9
0.68 - 1.00
0.30 - 0.33

You need to have an ohmmeter to measure across the sensor (with the connector removed). Check the connections too.... if the connector is all gooked up and corroded, this could cause higher readings to the ECU and give more fuel dump.

If you end up removing the sensor, don't forget to bleed the cooling system.
Sensors are free if you have a buddy with just about any type of late model
Nissan, just don't tell them you swapped them 8-).....

Everyone should remember that the water temp sensor is just a starting place..... it's just one of 30 things that could go wrong with E.F.I. systems (bad MAF, leaky injectors, corroded connectors, idle switch, bad TPS, etc....) I think every back-yard (or carport) mechanic needs a real shop manual and a multimeter to easily diagnose most F.I. problems.

As I said above... a friend's donor car doesn't hurt either.
Dave Balingit - Data Tech Racing
| 240SX Pacific Coast Touring Car
| [email protected] : [email protected]