Funny Filter

[Buick Beginner]

Gentlemen,
I was over at a buddy's house this evening who is also running an '87 GN and i was just looking around under his hood and noticed that on his waste gate solenoid, one tube had a vacuum line on it which ran to the compressor and the waste gate. The other tube sticking out of the front, had a small filter on it. Now wait a minute. My second little tube sticking out of the front has been capped with a rubber cap. My buddy says, "No, it is supposed to have a foam filter on it." I removed the cap thinking, "I wonder what effect this has on boost?" I got out on the open road on the way home and nailed it from about 10 mph. To my horror, I watched my boost gauge shoot up to 23 pounds of boost and my knock dectector went beserk! Can someone please expound upon this situation? Apparently the previous owner/abuser installed the cap and not a filter. What gives?? - BB

 

[TurboRegal84]

Your buddy was right, there should be a little foam rectangle on there, or usualy it falls off, and you can run with the port open.

 

[Mr URL]

Passenger side wastegate solenoid connection goes to the wastegate hoses "Y". "Y" connection with the restrictor goes to the turbo compressor housing. The non-restricted part of the "Y" goes to the wastegate actuator. Drivers side solenoid vent is open with a foam filter on it (normally but it falls off). The ECM uses the solenoid to bleed off pressure to the wastegate actuator into the air. Less wastegate actuator pressure the less it pushes on the wastegate causing it to raise boost. When you capped it off all pressure was going to the wastegate actuator. You then raised your boost level by making the wastegate actuator rod shorter or tighter. That is called "tuner style" and had no ECM boost control.

Uncap it and lengthen the rod until you get the boost pressure you want lowered. ECM then can have some control again.

 

[Buick Beginner]

Outstanding Information

Thanks for the info. Much appreciated!! - BB