Wastegate Actuator testing question

[Jess_sr]

If I unplug the vacuum hose to the Wastegate Actuator and apply vacuum up to 28" from a hand pump shouldn't I see the shaft move into the actuator?

 

[Big T]

If I unplug the vacuum hose to the Wastegate Actuator and apply vacuum up to 28" from a hand pump shouldn't I see the shaft move into the actuator?

Place your mouth on the plug, alternately sucking and blowing on it (like a good woman) and you should see the actuator move. If not, then resolve to the fact that you're a man.......no that you either have a cracked vacuum line or the actuator is out.

 

[SmithvilleD]

When the engine's shut off, the actuator is already moved to it's limit in the direction the actuator's internal spring pushes it - wastegate closed. Pulling vacuum can't move it any further in that direction. If it holds the vacuum, you know the diaphragm isn't leaking.

With the engine off, to understand the action (with less intimate personal involvement):h,) push the actuator rod towards the cab (overcoming the internal spring), then apply vacuum & it will pull the rod back - closing the wastegate.

The OEM vac/solenoid system varies the duty cycle of the boost solenoid, to vary the vac/actuator force pulling the wastegate closed. So when a vac line or pump fails, there's not enough force to hold the 'gate shut & low/no boost.

 

[540s10]

When the engine's shut off, the actuator is already moved to it's limit in the direction the actuator's internal spring pushes it - wastegate closed. Pulling vacuum can't move it any further in that direction. If it holds the vacuum, you know the diaphragm isn't leaking.

With the engine off, to understand the action (with less intimate personal involvement):h,) push the actuator rod towards the cab (overcoming the internal spring), then apply vacuum & it will pull the rod back - closing the wastegate.

The OEM vac/solenoid system varies the duty cycle of the boost solenoid, to vary the vac/actuator force pulling the wastegate closed. So when a vac line or pump fails, there's not enough force to hold the 'gate shut & low/no boost.

the wastegate actuator is supposed to have a spring in it?

 

[SmithvilleD]

Something internal lightly pulls the actuator back/retracted when there's no vacuum connected. I haven't actually torn one apart, but a light internal spring seems more likely than intrinsic tension in the diaphragm material.

Whatever develops the return force, it's small compared to, say the force of a 15 psi external wastegate spring.

I have to stop & consciously remember it's a vacuum system. Force of habit makes me first think of the more prevalent boost pressure (overcoming an internal spring) wastegate actuators.

 

[TurboTahoe]

It's easier I think to just apply a vacuum gauge to the line from the vacuum pump and see if you have good vacuum, then apply directly to the wastegate to see if it works properly. If there are no leaks in the line, and the wastegate works fine, then its the actuator dying on you.

-Rob

 

[BigBlueChevy]

Jesse! Glad to see you made it over here in one piece. Remember the solid axle swap I was telling you about? Its coming down to the wire Now its all the small crap I gotta take care of. Perhaps I'll swing by to show it off. Assuming I can manuver through to aamco without turning someones car into a pancake...

Take it your sons truck is causing more issues ? its pretty easy to tell if its working or not. Move the arm up and down without the engine running or with the hose attatched. Should move freely. Now put your finger over the hole the hose connects to. and try to "force" the air out. A good can wont let any air by.

 

[Jess_sr]

Thanks for the info guys.:thumbsup:

And no I'm not putting my mouth on the actuatoruke:h

 

[Big T]

Thanks for the info guys.:thumbsup:

And no I'm not putting my mouth on the actuatoruke:h

Not the actuator, the vacuum line plug to the wastegate solenoid. Unplug it and stand over the actuator itself and alternately blow and suck on it and you should see the actuator move.

 

[Jess_sr]

Not the actuator, the vacuum line plug to the wastegate solenoid. Unplug it and stand over the actuator itself and alternately blow and suck on it and you should see the actuator move.

I'll get my son to do it):h
After all, it's his truck.