I am trying to track down the reason for a serious stumble under load (idle is fine) in a 940 Turbo. I pressurized the intake and hear air escaping from under the intake manifold. I have isolated all the rubber tubing under there and so it does not seem to be coming from anywhere. I hear the air but can't pinpoint it. So am beginning to believe that the process of elimination means it is the bottom part of the gasket. I put soapy water over the manifold, but there are no bubbles. So do I just order a gasket and try that?

Thanks for any help.