I tested my coolant temperature sensor and I'm getting slightly below 200 ohms at normal operating temp. I think it was like 190. Is this a big deal ?

The specs are 200-400.

 

Honda ECT thermistor resistance range;
20kΩ @ -20°C (-4°F)
0.1kΩ @ 120°C (248°F)



So at 0.2kΩ that would put you in around the 100°C - 110°C (212°F) range. For the sake of 20°F you should be good to go. If you want to be 100% you could go back and verify the temperature of your coolant. I usually remove these sensors for testing and put them in a container of warm water. I take the temp of the water with a digital thermostat and compare it with the resistance that I see on my Ohmmeter. That way you can get a true comparison.

 

I think that that's what I'm going to do.

 

Did you bring it to operating temp first?

When I tested mine I got .342.......yours seems low.

Also you are making sure you are touching the 2 outputs correctly, hard to see in there.

 

How do you know when the engine is at operating temp and how do you tell what temp is it at exactly? Besides measuring the ECT sensor...lol

 

Well you can est based on letting it run until the gauge gets up to normal operating temp.

If you want to get technical you can use a scan device in the obd port to get the temp etc.

 

Cooling fans come on twice. That's what most Honda Manuals will tell you.

 

That's all fine and good if your ECT sensor is working properly. However, this test is to check if it is working properly. Not very reliable to use the signal sent from the sensor that you are testing!

What is normal operating temperature? 180-190 or maybe 200? I think that is why Honda gives a 200 ohm range for testing the ECT sensor.

All I am saying is that to do a more accurate test of what the ECT sensor is seeing. You need to have an independent temperature measurement of the fluid it is in. If the manual says you should see between 200-400 Ohms and it is between that.

Sorry for maybe getting a bit more technical than need be. Some people may like to test there equipment more thoroughly than using a 200+ Ohm range.

 

For the most part, if you let the car run up to 15 mins or so, it will up to operating temp, unless there is a thermostat issue etc.

The part is cheap (aftermarket that is), if it out of range I would just replace it.

 

 

I think that there is oil on the connector and the sensor pins that might be giving bad readings so I'm going to get it back to operating temperture and take the connector off back at the ecu and see what readings I get. The thing is I can't tell how exactly to test it.

http://www.ff-squad.com/technet/wiring.obd1.htm

It looks like D13 is the sensor pin so I'll put one lead on that but what do I put the other lead on ?

 

Try the connector again.

Just unplug it take a rag with electronics cleaner and wipe inside it. Then take the 2 probes and touch each terminal.

 

I finally found my problem. At one point during my swap, when I was having issues with the vtec pressure switch getting pinned, I had three computers, an A10, L11, and N01. I sold the A10, N01 while I kept the L11 as I need it to BAR it here in CA. At some point, since I'm gonna guess that it wasn't originally bad, I must have damaged the L11 and even when I fixed my vtec pressure switch issues, and idle issues etc. etc. the car doesn't advance/retard the timing correctly.

Today I bought an A10 from someone and threw it in and the thing runs like a charm. There are no misses throughout the rpm band like I was having with the L11 plugged in. It sucks 'cause I bought an egr valve I now know I probably didn't need, but at any rate hopefully I can sneak it past the ref without him realizing I'm using it. wish me luck