Hey I’m new here and have a problem with my 06 ss sc. I can’t get it to bullied any more then 4 pounds of boost and I don’t want to just got changing a ton of parts without some advise first. I think that it is the boost control valve but I’m not 100% sure. I have already changed the actuator but still didn’t change anything. What’s y’all thought

 

Sounds exactly like your bypass valve is open. Typically this is an issue with the bypass solenoid (mounted near valve cover on right side) that is plumbed to the bypass actuator or your ECU is commanding bypass solenoid off. I'm assuming you replaced the diaphragm actuator that is mounted to the supercharger and not the solenoid valve? If so you can bypass the solenoid valve temporarily to check if that is the issue. Pull the line off the diaphragm actuator but leave the other end connected to the solenoid then plug the line.

If you are now building boost then that is the issue though it isn't necessarily bad. Next step is to check and see if the solenoid is getting power when the car is running. The solenoid needs to be energized to make boost. If here isn't power there it is either because your ECU is commanding it or you have an electrical issue. If you do have power but your solenoid still isn't allowing you to make boost then your solenoid is likely bad.

You can test the solenoid by energizing it with 12V manually. When energized the port that is routed to the intake manifold will be blocked and the port that routes to the diaphragm actuator will be vented to atmospher. When non-energized the valve is normally open and routes directly from the manifold port to the actuator port.

 

Ok, so I have been messing around with this off and on for some time now. If I take one of the vacuum hoses off and plug the end - I get boost. But I haven't yet figured out why, I've replaced all the hoses, a sensor, a solenoid and the bypass valve. That's everything in that circuit.

The hose I removed was from the bypass solenoid to the bottom nipple on the bypass valve. Yes, I know that was suggested and in other forum posts. What I missed was plugging the bypass valve end of the hose as well

That gave me boost after about 4K RPM I got 12 lbs. I thought I might get more since I am running a 3" pulley. I was happy to see any boost at all.

I also don't think I am getting 12v at anytime at the bypass solenoid. I had emailed ZZP support about something else and I got this response.

"The LSJ has odd syncing issues. Eventually the PCMs just dont sync well with those solenoids and even fi you replace it, they wont work. the fix is to just leave it unplugged. "

Does that even make sense?

 

im not sure if you still respond to this but I have a couple questions. I have the same problem as you did. I unplugged the vac line from my bypass valve to solonoid and plugged the solenoid end of it. Are you saying I should plug the bottom nipple of the actuator/bypass valve too?
another question is with unplugging the solenoid. Are you talking about unplugging the sensor to the solenoid?