Misfire after sitting for six weeks

[perttu]

I stored the car for winter about six weeks ago. Today, I had to move the car. When starting the engine, it immediately misfired. I first let it idle, then put on a slight throttle and after couple of minutes things were smooth again. Fault codes stated misfire in two cylinders, but they didn't come back after clearing the codes and letting the car run. No misfires before this.

I'm not very worried for now, but what could cause this?

Spark plugs were changed about a year ago, the coils are original (2003). When rebuilding the CCV last winter, I noticed that the idle control valve flap was a bit stuck. I cleaned it and the flap moved fine again. Maybe it got stuck again, I wonder if the ICV can cause misfires?

 

[enuff_zed]

I doubt the ICV would only cause misfires in two cylinders.
Possibly damp highlighting a couple of weak coil packs, or slight leaks from the injectors on those cylinders.
Maybe leave it again then pull the plugs and see if those two are wet.

 

[raymond.harper]

Sticking valves, moisture, or unburnt fuel could cause the misfire. My general rule is at least a six-mile journey to get things flowing!

 

[B21]

I doubt the ICV would only cause misfires in two cylinders.
Possibly damp highlighting a couple of weak coil packs, or slight leaks from the injectors on those cylinders.
Maybe leave it again then pull the plugs and see if those two are wet.

I concur….