Author Topic: Lines running from Vacuum Pump Check Valve on 95 Jetta (Read 2029 times)

homerj1 · « **on:** July 09, 2008, 03:21:12 pm »

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

Vincent Waldon · « **Reply #1 on:** July 09, 2008, 03:51:28 pm »

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 ;-)

homerj1 · « **Reply #2 on:** July 11, 2008, 09:45:46 am »

Once again Vince, thanks!

Aivars

Tintin · « **Reply #3 on:** July 12, 2008, 08:06:38 am »

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)