Coolant Temp Sensor
I had been experiencing hard cold starts, leaving my garage in a cloud of smoke and embarrassing my kids ever since the weather turned cooler.
I was finally able to disconnect my coolant temp sensor, (damn that connector) and ever since then it has popped right off each morning while disconnected.
Last night I finally got around to replacing the sensor with one purchased from ID Parts. To my surprise, this morning it was back to its old ways, long time to turn over, lot of unburnt fuel smoke. Starts fine all day afterwards.
Oh, its a mk4 2001 Jetta.
No Vagcom handy.
2001 Jetta TDI