Getting SSV stuck open

Verified both ssv and vdi are stuck in the wide open position.

removed upper manifold and confirmed the vaccum chamber holds a vaccum at 20psi for 5 minutes

tested the ssv and vdi solenoids by removing them, capping the top, pulling vaccum, then adding 12v supply and it releases the vaccum pressure.

the only way i can get the SSV and VDI to release vaccum and return to the closed position is by manually removing the vaccum lines and they drop down.

i removed the lower intake manifold and completely cleaned it before installing my engine so i know that both the SSV and VDI move freely and theres zero carbon buildup inside.

i repeatedly tested the SSV and VDI with vaccum pump and they operate perfectly

for some reason they will not relieve vaccum while connected back into the engines vaccum system. As soon as i drive the car, they open back up, get stuck, and the car begins to studder, heavy power loss, and driveability issues.

ive scoured the forums and havent seen anyone with this issue.

ive ordered new solenoids, even though i bench tested the ones that are on the car. i understand that sometimes moisture or temperature can interfere with electronics. Maybe they stop working once the car is at operating temp, but as soon as its cold i cant diagnose?

HELP

TLDR: everything work but car no work

 

Sounds like something is blocking the solenoid's relief port. There's a removable plastic silencer on the back, this thread explains https://www.rx8club.com/series-i-do-...lenoid-190364/
AFAIK the solenoid should pass intake vacuum when energized, and pass to atmosphere (the silenced back port) when de-energized. You seem to be describing the opposite?

 

Thats exactly what i did to test the solenoids and they work just fine,

Either the car just isnt telling them to do anything

Or like you said theres a clog.

the car just wont vent the vaccum to atmosphere

 

Are the silencers on the solenoids only vaccum caps? Or are they not fully sealed to vent the pressure? Because when bench testing i couldnt get the solenoid to hold vaccum without taking it off, and plugging it

 

They should be open to atmosphere, just muffled to avoid annoying whistles every time you open the vacuum. If they were capped, you would trap vacuum behind the solenoid when it closes and the valve it controls would never close. Which sounds like what's happening?

 

im going to run the car without the silencer caps and see what happens

thats for pointing me in a new direction