boost problem

[rogerstrampoline]

I think I might try the actuator problem first and see how I go with that any way of doing that without removing it from the car?

[DavoAust]

Originally Posted by maztech

Funny that I have seen it before on a BOV not operating correctly -- But anyway -- Example the factory Bosch ones you find around had a faulty batch causing spike

I'd be very very surprised if thats what was causing the spikes. The only direct way that could happen is if the factory BOV was set up to constantly bleed air to smooth the boost curve out (or to prevent surging at a low rpm/high load boost). Anyways..

I'd hook the wastegate to a Tee piece off the manifold along with the boost gauge. That way you know exactly pressure the wastegate is seeing (bar any kinks or damage to the line to the WG). If you get past 7psi:
- The hose is rooted, maybe something got blown through and is blocking it. Slightly bigger hose can make it more responsive to changes
- WG is jammed. It happens, especially if it hasn't been used in a while. They're pretty simple to pull apart and is worth a look/WD-40 if you find its the problem
- WG has been modified. Was it you that had the previously welded wastegate? Did you check it opened smoothly?

[rogerstrampoline]

Wastegate is currently run from a thread just after the turbo and before the intercooler (didn't plug it into the intake manifold) as my bov line runs to the intake manifold.....might run a new line for the wastegate first and test it then next week I guess take the turbo and manifold off to get to the wastegate
Could the problem also be that i havent plugged the wg into the intkake manifold?

[derb]

My gate is plumbed from the intake manifold, shouldn't be a problem. See if the actuator arm is bent or rubbing on anything perhaps stopping the gate from opening and causing boost spikes. You should be able to pull/push on the gate arm and have it move a bit. You won't have the strength to fully push it in I don't think, but at least see if the arm is moving.

[DavoAust]

Originally Posted by rogerstrampoline

Wastegate is currently run from a thread just after the turbo and before the intercooler (didn't plug it into the intake manifold) as my bov line runs to the intake manifold.....might run a new line for the wastegate first and test it then next week I guess take the turbo and manifold off to get to the wastegate
Could the problem also be that i havent plugged the wg into the intkake manifold?

Yeah that could be it. The wastegate isn't seeing the actual pressure due to the velocity of airflow in the pipes. You're normally supposed to run them off IM (or close by).

Head down to autobarn, grab a t-piece, a vacuum line connector and a length of vacuum line. Put the T off the IM line and run one to the WG, you can use the connector to extend the line temporarily so you don't need to pull everything apart.

Where do you have the boost sensor? That should be IM pressure too.

[rogerstrampoline]

Got my graduation now but this arvo or tomorrow ill change the wastegate line to a better one and run a line from the intake manifold down and yeah my boost guage is hooked up to the intake manifold......
What should I do with the thread I tapped into my ic piping before the ic though?

[DavoAust]

What sort of thread? You can get vacuum nipple caps, maybe get one that covers the nipple and then hose clamp it on so it doesn't blow off.