I have a 2009 XK Coupe with 77k on it. Over the last couple of days when starting it on occasion it seems to be starting oddly. Its almost like its missing on one of the pots. Its not happening all the time though.

Any one else experience this? Ideas?

 

Does this only happen during the open loop cold start . Does it go away after the engine goes into closed loop when the idle drops to normal.

 

Fuel Filter would be due if not done already.

 

Is the "check engine" icon illuminated? Could be one or more cylinders misfiring at startup. Happened recently to me, but of no consequence. Checked the fault codes with my OBDII reader, cleared them, and it hasn't happened again.

My XKR is not a daily driver, so the spark plugs can become fouled but are easily cleaned with a few hard acceleration runs on the interstate.

 

Car was warm. Had been driving for an hour and after a nice freeway sprint. I have just filled the tank to the top with premium gas at Sams. I just read a post about winter fuel that might make sense. So I started it 3 times with rough idle then when I double pushed the gas it went away. drove it 20 miles with no problems. Then stopped at store it was fine.

No check engine light. It idles at about 650 rpm (which is normal). It was just dropping off and dying. The after a rev or two went back to normal. Its happened once before.

I was thinking its the gas.