EFI, have both the PCV and distribution manifold hosed to connections under the upper intake. Only take-off from distribution manifold is to fuel regulator. When I hook up the vac gauge to distribution manifold and start the engine, vac jumps to 20" then slowly recedes to the 9-11 range and hovers there. I've checked all hoses and have sprayed starter fluid (ether) all around with no effect on revs. Anything else to look for, diagnose?