1987 Chassis Buick Service Manual vol.1, page "6E3-A3-90 Driveability and Emissions - Fuel Injection (Port)", is trouble shooting the EGR page when you get a code 32. Even if you don't have a code 32, it has very useful diagnostic info to help pinpoint the issue. But from what you posted, you might already be working from this page.
In this link, you want to click on 6-Engine.pdf and go to page # 218.
This gives the overview and circuit description.
https://drive.google.com/drive/folders/0Bw1XeaDzY7DlSUVHaFRsNEN1clk
There is also another page with the same name just different page number that exists. But it depends on which version of the service manual you have. It's the same info as above. Page #, "6E3-A4-68"
I would start by checking the obvious items, like the vacuum hoses that may be heat cracked or leaking that feed the solenoid, all of your wiring and the fuseable link that powers it. But I'll be honest, I have never had to diagnose an EGR failure or in-op condition on any of the cars I've owned. Typically, this particular system is one of the first things that finds a home in the spare parts box. But I feel your pain. Especially if you are having to deal with emissions and it won't pass because of a mechanical / electrical issue like this.
Maybe someone else can chime in whose had to deal with this before.
Hope some of this helps.
-Patrick-