Ford Repair: Rough idle when cold, cold question, crown vic

Question
QUESTION: Hi, I have a 2000 Crown Vic LX (V8), the engine idle is rough (low) when cold, in park or in gear. It sounds like the engine is going to stall. The idle improves (or sounds normal) if taken into neutral. No CHECK ENGINE light has ever been triggered. I understand this is tough to diagnose without hooking up to an analyzer but would appreciate any info you can supply that may lead me to correct the issue.

Thanks for your help,
JG

ANSWER: JG, Does the engine gets better when the car warms-up.  Also, does it improve when placed into neutral while the car is cold?  or when it warms up?  I am bitt puzzled as to why the check engine does not come on, as this clear engine problem....  If you wanted to do a simple things, change the plugs and wires, then filters (air, fuel...).  If the problem cotinue, then I would suspect it might be a fuel delivery issue.  If you live in a cold climate, try to add a fuel additive for cleaning fuel lines first....  Good luck!  Thanks

---------- FOLLOW-UP ----------

QUESTION: Thanks for the quick reply. I'm very puzzled why the check eng light has not been triggered. Yes, once warmed up, no problem. Yes, it improves when placed into neutral while the car is cold. This only happens during winter time, it runs ok in the summer.

Thanks,
JG

Answer
JG, based on your latest feedback, I would recommend that you change the igntion coils.  I am suspecting that some fo them are not working properly.  However, I would start with the fuel cleaner first, then move on the igntion system.  If you have not done so in awhile, try changing the wires, plugs and igntion coils.  Thanks!