rough idle at start-up

[silver road hog]

hey my '05 bonnie gxp runs rough at start up, once it idles down though its smooth as glass any thoughts on what could be causing it, i've only had the car for a couple of weeks.

[repinS]

Hey, welcome to the forum! I'll move this to the GXP section to help get you the help you need.

My GXP kind of does the same, especially on warm startup.

[mike2fix]

This seems to be pretty common and has been attributed to a faulty ignition coil.

[CMNTMXR57]

It's normal. It's actually not "misfiring", it's just running rough. If it were misfiring, your cycle counter would pick it up and eventually flash a P0300 and corresponding cylinder P030x code.

COuld be from dampness, could be from cold (more prevalent for us in northern climates), could just be a bad contact initially. My guess, is in winter, it has more to do with the quality of fuel (most northern locals will go to a "winter blend" or RFG fuel, atomization of said fuel on cold combustion chamber parts, and or the injector itself.

As long as it goes away after a minute or two, I'd consider it normal. If it's noticeablly misfiring, and your check engine light is on, then yes, it could be a fautly coil module, clogged fuel injectors, etc.