stalling on 1994 Mercury Grand Marquis

engine stalls while waiting at long traffic lights.
engine Hot
A/C off
Transmission in D
starts no problem right after
180000 Km
plug and wires :new
Any ideas?
Thank you

Asked by for the 1994 Mercury Grand Marquis
Your air induction system is sludged up, especially your idle air control motor and passages. You need a complete fuel injection service.