2002 DF-140 No water pump pressure

Need some help folks. I recently replaced the water pump kit on my 2002 Df-140 suzuki. To my knowledge i did it correctly and replaced all parts as they should be. The lower unit has a Bobs High Performance low water pick up on it, I was careful when replacing the lower unit, the water pick up is lined up with the pump. The impeller turns clockwise and the fins of the impeller are turning the correct way. The impeller is the same size as the previous one. When water is hooked up to wash out on side the tattle tell sprays water and when I force water through the lower unit it sprays out of tattle tell. The key is in place on the shaft with the impeller. The base plate is on correct with new gasket applied. I've come to the conclusion that there is no blockage, pumped air back through the tattle tell and its clear. It just seem that the pump will not create pressure, even when lower unit is completely submerged. I am about out of ideas and I am looking for help. Has anyone encountered this problem when changing out a water pump? Any advice is appreciated.

It wont build pressure until you take off. In fact, you'll needto be on plane to build 10 or more psig, if hou have a vauge at console. WOT is where mine kseps the highest pressure.

Located on the side of the oil pan is a small cover held by two 10mm head cap screws. Behind it will be the pressure relief valve. The spring is proberly broken or it is open due to debris. Repair or replace. Thanks Martin

I have the same problem with my 2004 Johnson/Suzuki 4 stroke. Where does the water go if the pressure relief valve is open? I get no water coming out of the prop when I have the muffs on.