1993 Jeep Grand Cherokee Hissing noise when accelerating

1993 Jeep Grand Cherokee
4.0L 6 Cylinder

Whenever driving, no matter what gear, I get a hissing sound whenever I press the gas. I'm thinking it's some sort of leak, as it sounds sort of like a "spraying" noise, but more so a hiss. When idling, it isn't there, or at least it isn't loud enough to hear. What could cause this? Sounds like you have a substantial vacuum leak. Try to get a vacuum diagram and trace all the lines, the rubber ones are likely dry rotted and leaking. Where could I get a vacuum diagram from? Would one be in one of my manuals? (Chiltons/Haynes). I wouldn't doubt that one of the rubber ones is rotted, as I just replaced all 6 spark plug cables due to the same problem today, and it improved the performance a GREAT deal. I'm sure the plug wires helped, if they were that bad it probably looked like a lightshow at night under the hood. BTW, Chilton/Haynes should both have your vacuum diagrams.