16/01 still...st215 caldina beams 3s high/surging idle

[matt dunn]

My bet would be all related to a bad temp sensor.

They are pretty cheap to buy so bang a new one in there.

Have seen idle faults etc where testing them and checking codes and live data all shows ok,
but a new one fixes it. Worth a shot for about $40.

[xsspeed]

Cheers, I pulled the existing and gave it a clean, which had an immediate impact in fixing the idle issue for 24 hours, then it proceeded to do all kinds of weird idle 'control' that it hadnt been doing previously followed by some pretty consistent running. When it "fixed" it, I was hoping it was a case of air at the sensor pocket and I'd inadvertently bleed it.

Anyway, got a new one from Mark so will bang that in tonight

[xsspeed]

No dice, after about 5km of driving a mix of 50kph and a short stint on motorway at 100, check engine light comes on and it starts to idle high again.
Once its been turned off, when i start again the CEL is off but high idle remains.
Time to start pulling the codes i guess, open to other suggestions