01 sable cold idle issues
Hi, I am new to the forum, but, think I'm going to be on here ALOT! I have a 2001 Mercury sable ls, with a 3.0 duratec DOHC that I have owned since 40,000 miles. It has 139,000 miles on it now, with not much trouble. At 100,000 miles, I replaced the plugs and wires. I couldn't get the back 3 plugs out, so i removed the upper plastic plenum. Changed the plugs and realized I didn't have the 6 new oval gaskets. I replaced the plenum and it ran perfect. That winter, when the temperature got colder, the car, would start idling fast, only when first started. After it warmed up, it would idle and run fine. I changed the 6 oval gaskets with brand new ones, (assuming it was sucking air through the old ones when the motor was cold) It didn't fix the problem. If you come outside in the late fall or winter months and start the car,,,, on initial startup, the cars idle will go up to 2000 rpms and fluctuate between 1000 and 1500. Sometimes it will "load" up on fuel and puff black smoke. After about 10 minutes it will idle fine, and start and idle fine all day,,,, as long as the engine is warm. In the summer time,, no problems at all. It only occurs in the winter and colder mornings. It has set a trouble code once in a while. Its something like,"lean mixture on bank 2, O2 sensor 1"..I unhook the battery and it will clear itself for about a month and reappear again. But the idle will do that all the time. Any suggestions on what and where to look.