[car911]

I was driving my 85 NA 944 at speed (70mph+) when the engine started to run extremely rough. This persisted for a few miles.

I finally pulled over, turned off the ignition for a few minutes.

It started, ran very rough and rpms speeded up and down wildly for a few minutes.

Then, within a couple of minutes, it ran more and more smoothly until it ran normally.

Since then, it has run perfectly normally as if nothing has happened.

What can this be? Clogged injectors that suddenly unclogged? Blockage in the fuel line? Timing belt? (I can't imagine that). Airlock in the fuel line? Temporary scramble in the computer chip?