Stan, that is most definitely a suprise.In my early diesel tuning days, I had maxed out a wastegate bleed valve, only to get 12 psi. As soon as I plugged the pop-off valve's outlet line, it jumped to 27. I suppose it's possible that your inj. pump's setting is anemic enough to limit boost to that level, though it seems unlikely. I think you said that the wastegate is disconnected. If it's a garrett, there are two lines going to the wastegate. Are they both disconnected? Perhaps the wastegate valve is getting blown open by the exhaust pressure... I wonder what would happen if you routed boost pressure to the wastegate line that normally senses pressure at the compressor inlet? would that act to help keep the wastegate valve closed?