TS2 operating temps, How quickly? Options

[RustyWa]

For you FI guys.

How quickly should the CHT get up to operating temperature? You know, how quickly from 2.5Kohms @ 68 deg.F to 100 ohms or what ever it is at "operating temperature".

I need to test mine again, but I'm wondering if mine is dropping to fast.

[Anton]

I have exactly the same question. Why?

My 1.8 L-jet was running badly (low and irregular idle, decreased acceleration) the last two weeks in Italy; the typical temperature over there was 36 degrees Celcius (contrary to a modest 20 degrees back in Holland).

The temperature gauge was in the (upper) fourth quarter range while it is typical in the third quarter range.

I have heard of a too low resistance of TS2 at high temperatures producing a lean mixture.

What do you Californian and Florida guys say to this?

[Anton]

Test results of my TS2:

@ 15 deg.Celsius (which is below 68 deg.F) I measured 1.8 kOhm quickly dropping to 50 Ohms after driving for 10 minutes when the oil temperature gauge was still within the first quarter of the scale.

I interpreted this as a too low resistance, ie., a worn TS2 and ordered a new one.

Hopefully this will correct the low and irregular idle and rough running engine at high engine temperatures.

[Anton]

Adjunct to previous postings:

I put a 1 kOhm potentiometer (electrical resistance) between the old TS2 and its connector; turned it to about 0.3 kOhm (300 Ohm). A 0.2 kOhm value was still too low in MPO.

This dramatically improved engine performance; cold and hot starting is better, idle is definitely more regular, and acceleration has improved. What it will do to gas mileage I can only guess... (IMG:style_emoticons/default/rolleyes.gif)

Still curious to what a new TS2 will do, but it hasn't arrived yet. I found out that TS2 has a so called NTC or negative temperature coefficient and wears over time so that resistance will decrease.