I have a old body style 1999 Jetta. The car drives fine but when the A/C is off the rpms bounce from 900 to 400 then back to 900 and so on when at idle. When I turn the A/C on it really idles rough and sometimes stalls out when at idle. I replaced all plugs, wires, cap and rotor. I really need some help. This is starting to get on my nerves. Thanks Travis

If anyone knows what this possible is email me at roadrunner_19_va@yahoo.com

This might sound really wierd. But try taking the A/C relay out.

Read some of the threads on how to clean out your throttle valve.