Loosen the 10mm lock nut and back out the centre screw all the way.

You must check that the boost pressure is getting to the i/p through the banjo bolts and hoses across from the intake log and across the boost cut-off relay..next to the brake booster.

Most see boost between 9 and 12 psi. I run mine at around 19 psi.

Others will chime in with info' and links to previous posts about extra boost adjustments....it's been covered many times.

You may need to adjust the i/p load stop and torque screws too.