91 500sl idle lopes for 2 mins
 

The following problem started last week when it got cold. I live in Northern Virginia. The average morning tempretures are between 40 and 50 degrees. This problem does not exsist at noon or when the car is warm or hot. Only when cold.

I have a 91 500sl...when I start the car in the morning..(in neutral/park)..the idle lopes for about 2 minutes... that is the idle increases and decreases in speed from 600-1500 rpm.

To describe it a little better, when cold,.. the car starts at +/- 600 rpm, it then jumps in rpm to +/- 1500. As soon as it hits 1500, it drops to 600, and this fluctuation goes on for about two minutes.

Common sense tells me its a tempreture sensor of some sort...but insight and experience tells me it cant be a temp.sensor because the two minutes of idling dooesnt even come close to budging the temp.

this is a two minute headache......any solutions?

perhaps a fuel temp sensor?