So, I was out in my 93 the other day and when the turbo switched over, the second turbo made around 5lbs if boost for about a second before falling to zero boost. Now, my first turbo has normal 9-10ish boost levels, but the second has none. What could this be? Vacuum line? hose, solenoid...etc?

 

Just from what I have observed reading on here for the last 10 years or so ( I absorb a lot of useless info..lol!)..
Check the intercooler piping to the Turbo..it is known to dislodge or come off and you lose secondary boost.

 

If the charge control valve isn't opening, this will also cause no boost when the secondary turbo comes on.

 

As above, start by looking for hoses, then check your solenoids, hopefully its a simple fix!

 

Low secondary boost can also result in the actuator arm being disconnected underneath.

 

low to no boost could be cause by the pre-spool and wastegate solenoid connectors swapped around.

Troubleshooting

 

Check your vacuum lines. Look for any leaks.

 

Thanks for the info. I will check on these this weekend when I can dedicate some time.

Brody, that link is fantastic. thank you