[PZ]

The SAIP does have the self-test of the solenoid and pump. You can test the solenoid with a vacuum gauge to see if it allows vacuum to activate the valve. Also, check the vac line to the reservoir as it can crack inside the cloth covering under the coolant tank. Low vacuum in the reservoir can cause the combi valve to only open partially.

 

[PZ]

There is a disconnect between the combi valve and solenoid, so it should not get carbon deposits. The exhaust would flow into the SAIP itself, causing it to seize.

 

[PZ]

On the vacuum reservoir that's mounted behind the fender liner, I found the rubber hoses were cracking. It was on the 01 B5 donor car and I decided not to install it with the swap. I also deleted the SJP, but kept the SAIP and did not have any issues with the brake booster.