Greetings from Greece.
I have a S5 FC3C '91 turbo II with 117.000km on it.
My compression is kinda low on one rotor and i am thinking about a rebuild.
The problem that my car has is the following:
When its a hot day and i get stuck in the traffic the engine SOMETIMES shuts down suddenly like i am shutting it of with the key.
Usually the rpm needle dives suddenly to 650k and then rises up again but as i said sometimes it shuts down.I repeat that the needle dives suddenly,brutally and fast....its not like the usual idle problems.
Does anyone know why this happens???
I have noticed that when this occurs the light in the gauges cluster trembles.
Can it be electrical???
Any ideas???

I thank you in advance

 

Anyone???

 

I'd say electrical. It kind of sounds like a short somewhere, but i couldn't say where. You might check the TPS and for vacuum leaks as that can also cause problems.

Do you have any mods btw?

 

The gauge lights always tremble when the engine is about to stall, and they all come on when it actually does stall. My guess is something isn't quite right in your idle control circuit.