Lines running from Vacuum Pump Check Valve on 95 Jetta - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• Lines running from Vacuum Pump Check Valve on 95 Jetta by homerj1 on 09 Jul, 2008 15:21
• As the subject suggests, I have two vac. lines that are connected to the vac. pump check valve. One in green, the other is a light brown in color.
  
  What do they do & do they need to be connected to vacuum?
  
  Thanks
  
  Aivars
• #1 by Vincent Waldon on 09 Jul, 2008 15:51
• On that vintage AAZ the most likely candidates are:
  
  1) to the cruise control.. on my beast that's the green hose
  2) to a solenoid valve mounted on the passenger side strut tower, which then leads to a black vacuum idle actuator mounted on the injection pump:
  
  
  
  On my car that one was light brown.  Its purpose is to up the idle... either due to the air conditioning being on or cold temps... prehaps both ?  Dunno for sure because the wiring to the solenoid valve was disconnected on my beast and I deleted all the vacuum stuff hanging off the pump.
  
  BTW... on some MK3s the cruise control has its own vacuum pump, so your mileage may vary ;-)
• #2 by homerj1 on 11 Jul, 2008 09:45
• Once again Vince, thanks!
  
  Aivars
• #3 by Tintin on 12 Jul, 2008 08:06
• If your car are equipped with the K03 turbo, there are a vacuum device acting on the turbo actuator to keep the wastegate open from 0 to around 1/4 throttle,  if not you get 10-15 psi of boost in light load normal driving (too small turbo)