Idle Fluctuation
 

I have a 99 with just under 58k on it, and it has intermittent spells where the idle will get rocky and bounce between 800-1000rpm, at a red light, for example. Is this semi-normal? I plan on taking it in at 60k and getting a full tune-up, etc. Should I look out for anything specifically?

Your car is non e-gas. At a work on cars day we had a 996 non e-gas show up with the same problem. No check engine light.

There is an idle stabilizer valve bolted to the throttle body. We removed the valve and it was loaded with carbon, which we cleaned with brake cleaner. The owner went for a test drive and said it was fine when he came back. This was about 2 weeks ago and I have not seen him since so I do not know if that was a permanent fix.

There are other reasons for a hunting idle, but in this case the only cost to find out if it was the valve was a can of brake cleaner.

The cheapest fix to try is some gas line cleaner. I use Chevron with Techron cleaner and it has cured this issue twice. Worth a try at $5 a can and no harm done if this does not do it.

Thanks fellas, I'll try the gas cleaner first, and then the other method. I appreciate the advice.