engine/ tranni problems

[vigman]

I have a 93 Cherokee Sport that is currently experiencing a series of strange ailments. First of all the engine is idling at aprox 500 to 400 rpm, the tranni will not shift out of first until around 3000rpm at 25 mph (even when accelerating slowly) and there is a loud hissing/ buzzing noise coming from around the gas tank area. The engine idle and transmition problem started happening when I got stuck on the axles in some mud, my roommate thinks it may be caused by a vacume line leaking but i sprayed every hose I could find with soapy water and then with a wd-40 knock off and couldnt find any leaks what-so-ever, I even disconnected the master cyl to make sure that it wasnt leaking. If anyone has any ideas that would be great because I'm completly lost.

 

[bigalpha]

TPS.