Temp sensors.

[TVRleigh]

Hi could any one messure the resistance of the 3 senors
The brown and black ECU ones and the to the right of the disy for the gague.
If pos at cold and at the 90oC line. or what every your normal running temp is.
Thanks in advance.
Leigh

[adam quantrill]

Leigh - the thermotime one is a switch - it'll be open circuit at 90C.

If you seatch the forum I'm sure someone posted the engine temp sensor resistance for various temperatures. From memory 270 ohms at 90 but don't quote me.

Dunno about the sender for the meter.

[TVRleigh]

adam quantrill said:

Leigh - the thermotime one is a switch - it'll be open circuit at 90C.

Dunno about the sender for the meter.

Umm that's strange as will getting a resistance from the thermotine one,
Hope it not buggered as its 50 quid.

But i'll do a search.

Shame you was not going to rockingham, as I passed though cambridge.

Thanks again.
Leigh

[TVRleigh]

Well the thermotime seem to only control the Cold start injector, and I have this disconnected.

So just a very expensive plug.

Will take out tonight and re-test with heat gun and boiling water.

I found this info

According to the Rover Efi technician training manual the Efi temp sensor
has the following profile.

TEMP-------OHMS
-10°C------9100 to 9300
0°C-------- 5700 to 5900
20°C-------2400 to 2600
40°C-------1100 to 1300
60°C-------500 to 700
80°C-------300 to 400
100°C------150 to 200

also these graphs.
This seems to match gauge sensor.

This seems to match the above Efi info

[TVRleigh]

Ok I took my Sensors off to do some tests, with known water temp's
Brown Sensor seem to be a switch as such under 35oC its 50 Ohms and above its 220 Ohms.

Black sensor readings
30oC 2k Ohms
35oC 1.5 K Ohms
60oC 500 Ohms
70oC 445 Ohms
80oC 260 Ohms
100oC 200 Ohms

Main Temp Sensor that goes to the Gauge.
30oC 460 Ohms
35oC 390 Ohms
60oC 190 Ohms
70oC 225 Ohms
80oC 154 Ohms
83oC 147 Ohms
85oC 140 Ohms
90oC 137 Ohms
95oC 120 Ohms

Had a problems getting a stable 100oC

I will get some varible resisters and set at the same value to see what the gauge reads at the above values.

This way I know what my actual gauge reads with my sensors and know how far out it is. I can also make my own CD marker marks on the gauge for 80 - 90 and 95. this way I should have an exact way of knowing what the tempture is, within 2 or 3 degres.

[dwgriffith]

"Well the thermotime seem to only control the Cold start injector, and I have this disconnected.

So just a very expensive plug."

It is also the return path (electronically) to the supply for the extra air valve, so the eav will not function as designed.

[TVRleigh]

Well I think the extra air valve is usefull. so will leave it connected, but I do have the injector conector disconnected.

Does anyone know if the resistance values are correct for the brown thermo switch.
or is the black one the thero switch.