Surging @ idle when cold and temp gauge slight bounce
All of the sudden last week my car threw a P0128 code. Its related to the thermostat and or the ECT sensor. It than began to surge at idle when cold in the mornings. I decided to just pop in a new ECT sensor, but its still surging when cold.
Also, when its cold and surging you can see the dash temp gauge going up and down, varying probably 40-60* (within full cold and 210*) at any given point until the car gets to temp. I don't have a scanner tool at my disposal, so I can't really see what else is going on when this happens.
No additional codes have been thrown since I replaced the sensor.
I could take it to the dealer to get it fixed under warranty, but I'll have to pull the Harris Speed Works system out first...
-Eagle
weird effects (spark and fuel and idle airflow adders pushing).
Can you scan the ECT reading while it's misbehaving and see
if it's unstable? Could be the harness / connector and not the
sensor itself.
There is supposed to be a test you can run on the harness too, by jumping the connector with a 3amp jumper wire. Sounded kinda scary to me tho, so I haven't tried.


