A better day

Posted by Corey Thomas on Tuesday, September 20, 2011

I swapped the right rear tire with the spare tire as planned - the spare was an unused original style Pirelli on the matching rim.  I took an early lunch to get the car re-inspected and it PASSED the safety inspection so I'm happy about that.

Regarding the emissions, I was thinking about the coolant temperature sensor.  I tested the old and new ones on the stove before installing over the weekend.  They one performed as follows:

The relatively new one from the car (maybe I put this in 2-years ago):
100 deg - 2 kOhm
170        - .41
180        - .35
190        - .32
...however as the temperature increased it started shooting up to .5 kOhm.  Clearly a problem.

The new spare I had laying around:
100 deg - 1.1 kOhm
170        - .40
180        - .34
190        - .31
...and kept dropping and the temperature increased - I put this one in the car prior to my failed emissions test and could still smell the richness in the fuel

But the dirty old one I had performed better but not much different than the previous one:
170 deg - .38 kOhm
180        - .32
190        - .30
...and also kept dropping as the temperature increased.

So, I decided to fix it to no resistance by bridging the terminals of the sensor cable and in my estimation, basically a sniff test, the started running leaner.  Note that leaving the terminals open will result in full enrichment and the car will promptly shut off.

I'm not sure what this means: Are all my sensors bad; I there an ECU issue; is there still another source of over-fueling; or the fact that I use WaterWetter which is incredibly effective at lowering my engine temperature causing the CTS to continue enrichment?

This entry was posted on Tuesday, September 20, 2011 at 10:18 AM. You can follow any responses to this entry through the RSS 2.0. You can leave a response.