Weird idle please help

[///Bimmerfan]

Alright so one day I was coming home and when I went to put the clutch in to pull to a stop my tach went from 500k to 0k then back and forth and almost died so I reved it up and it started running normal, but it still happens here and there while driving. Anyone know anything that might cause this? Its pretty annoying
:(

[///Bimmerfan]

Anyone?

[UserError]

Checked your throttle position switch? It sounds like a classical TPS going open in the idle position. Another possibility is vacuum leaks, though that seems unlikely, given that the car runs fine while at part throttle.

[jlevie]

The initial suspects would be a bad or misadjusted TPS, a sticky ICV, and intake leaks.

[///Bimmerfan]

Ok thanks guys I will check those out. ;)