So I have been seeing a theme here on the boards, with mine too. The idle jumps when in neutral or park and lowers when in drive or reverse.

500-550rpm stable D and Rev.
1000-1100rpm fluxs a bit too P or Neutral.

I have checked the banjo dual brass vacuum fitting to the transmission as SteveBfl suggested in several posts. No issues.

Any other hot spots for vacuum leaks on these cars?

Do these cars have a load reduction/booster vacuum solonoid that craps out often?

Does the Idle stablizer valve have issues?

ALSO>>> Starts a bit rough when cold, idle hunts low rpm for 10 or so seconds.

Just need a little guidance good with Cis and Cis-e work on VWs

ChrisG on the VwVortex.com experimenting in the Merc world. Loving Merc ownership