We found this online, shared by someone who found it elsewhere.
(isn’t the internet great!?)
Thought it was good info that some of you may need or want to know.
The waste gate solenoid is an electronic bleeder that is pulsed by the ECM in order to control boost.
It functions by bypassing boost through the solenoid into the atmosphere.
As this happens, the amount of boost reaching the waste gate actuator is reduced and it takes more total boost to overcome the wastegate actuator spring.
Minimum boost is obtained when the solenoid is closed and not pulsed.
As the pulse width transmitted from the the ECM increases, the solenoid is effectively held open longer, more boost is diverted thru it, and the actuator is delayed in opening so that more boost is produced before the puck opens.
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Note that the waste gate solenoid has two ports.
one is connected to the “Y” hose arrangement from the actuator and compressor housing.
The other is open to the atmosphere.
From the factory, there was a small piece of foam attached to the open port as a filter.
It does not matter which port the “Y” hose is connected to.
This pertains to the intercooled cars only.
In the plastic “y”, one end has a small restrictor in it.
This restrictor is connected to the compressor housing port.
The hole in the restrictor is normally .045-.050″.
Boost control will not be right if the hole diameter does not fit into this range.
Some dealer replacements do not.
The function of this restrictor is to prevent the waste gate solenoid from being overwhelmed by the volume of the boost coming from the compressor port and thereby being rendered ineffective.
Connect the “y” in reverse with the restrictor leg going to the actuator and you will have 12# of boost with a stock actuator and about 17# with an HD model.
Shortening the waste gate rod will not do much in this case.
Get a crack or leak in the hoses and you may find your boost is way over the desired limit and it’s a good way to get some practice changing head gaskets.
The factory solenoid has been discontinued.
This number, ACD214-1073, which was used on the turbo diesels, will work in its place and is a lot cheaper than the $100-$200 that some vendors have been asking.
I understand the connector does not lock as original but the connector does plug into the solenoid.
This solenoid has two ports just like the original.
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This might help too, if you need to know how:
waste gate plumbing
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