My girlfriend has a 97 gtp with 190xxx on it. The car drives well and still has plenty of pep for it's age. The problem I'm chasing is upon startup (esp cold) the car will immediately fire up however it sputters for about 4 or 5 seconds before it settles to a normal idle. The tach will fire up to 900 rpms then immediately drop to four or five hundred irratically like it's about to die. It has all new fuel (pump & fpr) components and a very recent tune up all the try and cure this problem.

pleasee help, I don't want her stranded in the winter.
thanks.