The tech in Vancouver told me it should be around 1200 ohms. Another thing was to hold it steady and give it a slight tap , and see how far it jumps around before coming back, or if it just gives no reading at all. Mine was sensitive to tapping in certain areas of the sensor, closer to the magnetic end. One time, I had to touch the tip to a metal surface, kind of resetting it to get the ohm reading back
I tried testing the wrong new one sent to me, but because it was a diffferent #, it showed about 900 ohms. The correct new one I received today was around 1200 ohms, and as you mentioned, they increase with heat. The old one increased pretty fast around 1200 ohms,went up and up and then just crapped out until it cooled off a little, then read it again, crapped out as soon as the heat was put to it. The new one didn't increase dramatically when heated, just slowly went up. I never heated it much, but it seemed a bit more steady paced, when the old one just bounced right off the scale pretty fast. I am thinking maybe , especially on a warmer/hot day, the increase in temp around the sensor would cause the unit to fail faster, cut in and out more often, longer cool down time as compared to a colder, rainy day, when maybe it wouldn't even crap out at all? Just a thought, since we're dealing with a coil, or wire expanding with heat. I know on our snowmobiles, the CDI unit would do the same when failing, die when hot, reconnect inside and work again when cold, and eventually just die out completely. Tomorrow, I will take it on a drive, 120 km to another city, and back. I will post again what happens, if anything new, as it will be warm out again as well.