Oscilating cold idle

[smooth_eddy]

Something new has happended to my cold idle. My cold idle oscilates up and down between barely running and 2000 RPM. Eventually it dies and I have to restart the motor. When the car is warm the problem goes away. What is going on?





The photo does not really apply to the problem but I wanted to post it anyway. Eddy

[Bleyseng]

From looking at the picture your car was too close to the water and caught a cold!

Nah, its a vacuum leak somewhere thats causing the hunting.

Geoff

[pbanders]

May be a vacuum leak, as Geoff says. I'd also see if you have a lean warm-up mixture. This may be due to a lower than required value of CHT sensor resistance during warm-up. First, eliminate all vacuum leaks. If the warm-up idle still oscillates, try putting a 50 ohm resistor (1/2 watt) in series with the head temperature sensor (splice in using spade connectors where the CHT sensor connects to the wiring harness). You can use up to 100 ohms of resistance without affecting the fully warmed-up mixture setting.