Porsche Repair: PORSCHE 928, airflow meter, porsche 928

Question
I HAVE A RECURRING PROBLEM WITH MY 1986 PORSCHE 928. THE VEHICLE CUTS OUT WHILST RUNNING FOR NO APPARENT REASON. IT WILL RESTART IMMEDIATELY USING THE STARTER AND RUN FOR A MINUTE OR TWO BEFORE CUTTING OUT AGAIN. I HAVE CHECKED THE FUEL FILTER AND HAD THE FUEL PRESSURE TO THE FUEL INJECTION CHECKED AND ALL IS OK. WHAT CAN THE PROBLEM BE?

Answer
Hi Tom,

If you feel the problem is not fuel delivery...and it sounds like that's a logical conclusion, then here's where I'd look first.  This component goes by many names, but basically you have an airflow meter that measures the amount of air sucked into the intake manifold.  It gives this information to the computer, which then determines the correct amount of fuel to squirt into the cylinders.  The meter is actually nothing more than a flap covering an opening (between the air filter and the intake manifold) and it's the measurement of how far the flap is opened that actually calculates the airflow.

Now...if the flap doesn't move smoothly or gets stuck because of dirt, grime, and other foreign material, then the computer gets false messages.  If the computer gets a message that is really way out of line compared to what it expects, it will simply stop the engine to protect it.  Hence, the engine stops abruptly.

The fix is for you to get all greasy and dirty taking apart the air filter and airflow meter assembly, meticulously clean it, lubricate it and put it all back together.

Give that a try.

Dave