I was sitting in my car today talking to my girlfriend for about 30 minutes, the motor was running the whole time and I after a while I began to notice that my rpm needle was bouncing up and down from about 1000 rpms down to 300 rpms and the car was almost stalling. Eventually it stalled so I restarted it with no problems and the rpms began to do the same thing. I had no trouble driving it home but I'm just curious as to what is wrong.

 

That would probably be your Idel valve. I forgot the full name for it I...Something my friend just replaced his becuase thats what it did. ICV maybe?

 

mine did that before i took it in, the shop i took it to found multiplevaccume leaks and the DV was trash, i would make sure you have no vaccume leaks

 

It could be your air pump going out?

 

try ICV cleaning first since thats what controls the idle, then it wuld be a good idea to replace the vac lines, i had the same problem in my 96 a4, the ICV cleaning made the most diffrence.

 

what's an ICV?

 

mine was doing that while the MAF was dying

 

Idle Control Valve

 

maybe you need a new crank sensor??

 

The car seems to be fine now, but just in case i still want to clean the ICV. How would i go about doing that?