[RKDinOKC]

When my 914 did that I cleaned the Throttle Position Sensor, TPS to fix it. Was rather proud of myself for figuring it out. 2 dealerships and Dumont's gave up when they couldn't find it. On the 928 there is both the TPS and an Idle Stabilizer valve that can cause that kind of behavior. Would imaging there are temp sensors that can also cause that kind of thing.

What is most likely is that the last thing you worked on you bumped or pulled a wire to something else has now got an intermittent connection causing the rpm bump. Lets just hope it's and easy fix like that!

Guy in the 928 discussion group apologized. Was going thru all kinds of trouble shooting and getting help the car had died and wouldn't start. They were checking spark, timing, injectors, fuel pump etc. One of the guys that physically went to help him noticed the gauge was on E. They put some gas in it and it started up just fine. He was really embarrassed.