HEy guys its been a while since I last posted. I am looking at getting another second gen(Missed them a lot). The one I am looking at is a 10th Anni. The only problem with it is it has surging idle. The idle will jump form 500rpm to 1500rpm over and over. Does not matter if it is hot or cold. Sounds like someone keeps revving it.

Before I start taking it apart when I snag it, any ideas what it is? I think It could be the vacuum lines, but I could be wrong. Any insight would be great.

Maybe even throttle position sensor?

 

Sounds like a small vacuum leak if it is surging. Could also be a TPS out of adjustment.

 

In approximately decreasing order of liklihood:

Vacuum leak
Bad thermovalve and double throttle diaphram
Bad thermowax, fast idle system adjustment
Water thermo sensor
AFM
TPS
Intake air temp sensor

 

Thanks for the Replies. We think it was both the thermo-valve and a vacuum leak.

Again, Thanks for the help.