I'd suggest the following:

1. a vacum leak, anywhere, including at the intake manifold gasket.

2. mass air meter

3. throttle actuator

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".