Yes.
Look here: http://www.mkiv.com/specifications/ncf/ncf93/
Read from pages 88 on. If the sequential system is messed up, it won't boost much past .8 bar. You can follow he hose diagram on the underside of your hood and the description of the system in the link to help troubleshoot the problem.
Once you've realized all the silly things that can go wrong, look for the TTC mod in the tech articles section
Look here: http://www.mkiv.com/specifications/ncf/ncf93/
Read from pages 88 on. If the sequential system is messed up, it won't boost much past .8 bar. You can follow he hose diagram on the underside of your hood and the description of the system in the link to help troubleshoot the problem.
Once you've realized all the silly things that can go wrong, look for the TTC mod in the tech articles section