97 E420, engine runs fine when moving, but at idle the rpm is very unstable and keep dropping to 400rpm or so and wants to stall. it actually never dies but the computer will shoot the rpm back up.

can anyone please help.. is this a symptom of 1 part (CPS?) going bad, or something bigger..??

__________________
Current cars:
2001 MB E55 AMG
2003 Honda S2000
2000 Honda CRV

Gone but not forgotten:
2004 BMW 325i 5sp sport
1999 BMW 540i sport
1997 MB E420
1995 BMW M3 coupe

Sounds to me like a vacum leak or a bad mass air meter.

A crank position sensor will cause a no start problem with a warm engine.

__________________
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".

thanks.. some more info: the timing of this problem coincides with the recent much higher temperature around here.

also, when i tried to start the car today after work, it took almost 3-4 seconds of cranking to fire her up.. started ok in the morning though.

__________________
Current cars:
2001 MB E55 AMG
2003 Honda S2000
2000 Honda CRV

Gone but not forgotten:
2004 BMW 325i 5sp sport
1999 BMW 540i sport
1997 MB E420
1995 BMW M3 coupe

Scan the system for fault codes so that we may get an idea of what maybe happening.