Volkswagen Repair: engine trouble, volkswagon jetta, rubber hoses

Question
I have a 1992 volkswagon jetta with the 1.8 liter engine. Sometimes when i stop at a red light and have the clutch pushed in the engine rpms shoot up to 3000 rpms. Sometimes it goes higher. They only come down when i start driving. It even Does it when the car is parked. It's never done thaat before. Can you please help thank you. First Volkswagon and love it. I haven't done any repairs to it yet this the first problem that I've had with it so far.

Answer
Hi,  sorry for the tardiness but my PC is history.
You got a vacuum leak.  Best way to find these things is: first gotoWal-Mart and get a spray can of brake cleaner(it is easy on rubber parts and is highly flammeable)  With the engine running at a steady idle, spray all the intake points and connections in your engine compartment each one individually gets a wash of this stuff.  If the engine speed changes (higher or dies) that is your trouble spot.  And there may be more than 1.  Rubber hoses get hard and brittle so if you can't seem to find a leaking connection, try the curved length of a braided hose... or a clamp etc.   That is where your trouble is.