Is this normal actuator behavior? (overboost inside)

[Braga_Dub]

Short story:
When I start my car, the VNT lever moves about 1/2 way down from it's "no boost" position. I noticed this after trying to fix an overboost issue.
Is this normal?

Long story:
- Overboosting like a maniac under normal driving.
- VNT lever did not travel very much.
- Replaced vacuum lines, cleaned N75/Boost Valve, and checked the car with Vag-Com (Timing = retarded, but within spec )
- STILL overboosting!

Today:
- Opened the EGR port and sprayed a ton of PB (4 seconds of spray) in there.
- "Lightly" wiggled the VNT lever with an open end wrench.
- Turned car on, unplugged N75, wiggled lines, watched smoke leave my tailpipe.
- Plugged N75 line back in and went for a drive.
Rinse/Repeat

After doing this twice
- VNT lever was freed up, I could move it all the way, and it would bounce back to the no-boost position when I let go.
I rejoiced!

So I went for a drive.
- Still overboosting, but not as bad, and only seems to happen if I get on it or above 50%ish pedal.

So I went back to the garage, and with help, I felt the mechanism as my car was turned on. The VNT lever moved about 1/2 way down it's "full travel" length, and stayed there. When I unplugged the line from the N75, it would go back to the no boost position.

Anyway... Is it normal for the actuator/vnt lever to move on startup and stay there?

At idle I'm at "1/2 full boost" position, so I imagine that my car defaults to "1/2 full boost" when anything happens.

I've got a VNT17, boostvalve (not doing anything atm), and RC4.

Thank You!

 

[F1 tuning]

Short story:
When I start my car, the VNT lever moves about 1/2 way down from it's "no boost" position. I noticed this after trying to fix an overboost issue.
Is this normal?

Long story:
- Overboosting like a maniac under normal driving.
- VNT lever did not travel very much.
- Replaced vacuum lines, cleaned N75/Boost Valve, and checked the car with Vag-Com (Timing = retarded, but within spec )
- STILL overboosting!

Today:
- Opened the EGR port and sprayed a ton of PB (4 seconds of spray) in there.
- "Lightly" wiggled the VNT lever with an open end wrench.
- Turned car on, unplugged N75, wiggled lines, watched smoke leave my tailpipe.
- Plugged N75 line back in and went for a drive.
Rinse/Repeat

After doing this twice
- VNT lever was freed up, I could move it all the way, and it would bounce back to the no-boost position when I let go.
I rejoiced!

So I went for a drive.
- Still overboosting, but not as bad, and only seems to happen if I get on it or above 50%ish pedal.

So I went back to the garage, and with help, I felt the mechanism as my car was turned on. The VNT lever moved about 1/2 way down it's "full travel" length, and stayed there. When I unplugged the line from the N75, it would go back to the no boost position.

Anyway... Is it normal for the actuator/vnt lever to move on startup and stay there?

At idle I'm at "1/2 full boost" position, so I imagine that my car defaults to "1/2 full boost" when anything happens.

I've got a VNT17, boostvalve (not doing anything atm), and RC4.

Thank You!

disconnect the VNT vacuum line and drive, or better put a T and long line inside the car and wen the car overboost open the line and make go down to no boost position and see if the boost goes down, if the boost came down wen controlling manually i would call you tuner and ask to correct the issue

Read this and see if that's a match to you problem
http://forums.tdiclub.com/showthread.php?t=167772&highlight=skippytdi

 

[JPDiesel]

You need to do more testing.

1. Connect Mity Vac or similar to vacuum hose going to turbo. See if you get full travel of the actuator by 20 inches of Hg. If not actuator needs replacement or adjustment or hose is leaky.

2. Then T in your vacuum gauge (I used my Mity Vac as a gauge) to the line from the N75 to the turbo. Vacuum at idle should be greater than 20". If this is low, it could be leaky hose or bad N75 .

3.Measure vacuum going to the N75, at idle it should be 22-25 inches Hg.
If this is low the vnt may not be able to open all the way. Could be leaky hose or bad vacuum pump.

 

[F1 tuning]

You need to do more testing.

1. Connect Mity Vac or similar to vacuum hose going to turbo. See if you get full travel of the actuator by 20 inches of Hg. If not actuator needs replacement or adjustment or hose is leaky.

2. Then T in your vacuum gauge (I used my Mity Vac as a gauge) to the line from the N75 to the turbo. Vacuum at idle should be greater than 20". If this is low, it could be leaky hose or bad N75 .

3.Measure vacuum going to the N75, at idle it should be 22-25 inches Hg.
If this is low the vnt may not be able to open all the way. Could be leaky hose or bad vacuum pump.

You have overboost issue so unlikely there is leak or not enough supply in the system.
So all lead to the same problem from the start