Strange engine shut-off

[Lora Elbris <lora@pbunyk.physics.sunysb.edu>]

Hi, folks!

Today it happened to me for the third time in last couple months,
and I decided to ask for your advice. 

I drove at about 4000 rpm when I felt that my car (Audi Coupe '84) 
did not react on pressing the gas pedal. Car started slowing down... 
When I stopped on the shoulder, all warning lights switched on (as
when you switch the ignition on before starting the engine) and I
realized that engine did not work. When I tried to start the engine,
it started and worked fine. As I mentioned this have happened to me 
for the third time and it becomes annoying. Can someone give me
an idea what to check (electrical connections? Some stuck valve?)

Thank you,

Lora