The rear air ride on my uncle's 93 is sitting high and won't vent. Is this a solenoid issue? The check air ride is on.

Wouldnt be the rear height sensor come loose would it?

If it was a solenoid that was stuck, it wouldn't allow more air in or air out. Sounds to me like a possible height sensor issue.

the vent valve solenoid is located on the air pump

What air pump, the compressor?

neodon

That is correct but each bag has a solenoid that opens and closes also.

The compressor starts running and then the bag solenoids open to allow air, when the height sensor reaches the correct level the bag solenoids close to trap the air. When you turn the car off and close the door the bag solenoids open along with the vent solenoid at the compressor to allow the air to bleed from the system.

The bag solenoids have been know to stick.