The Air Flow Meter is located under the air box. It measures the amount of air entering the engine and tells the Fuel Injection Computer. While I was replacing the vacuum lines, I decided to change the gasket between the air flow meter and throttle body. This gasket will wear out, and since it's on the engine side of the air flow meter, it will cause a lean fuel mixture. It was used in 928s that had L-Jetronic Fuel injection (80-84 US models).
First I removed the Air Intake Tubes ( just slides off and under the cross brace , be careful of the stub on the timing belt cover ), then the Air Box cover and Air Filter. I also disconnected the vacuum hose on the passenger side. There are two 13 mm bolts that hold the air box base, remove those and the air box and air flow meter will lift out. Before you move them too far dettach the plug and wires from the air flow meter. It's alot easier to remove them both together. You can remove the 4 bolts that hold the air box base to the air flow meter, if you want to separate them.
Once the air flow meter was removed, the throttle body is exposed. The gasket is in the throat of the throttle body, in a grove. I had to use a utility knife to remove the gasket. I stabbed the gasket and lifted it high enough to get a thin screw driver underneath, then pried it out.
The new gasket fit right into the groove, I had put some silicon lubricant on the gasket. Then I replaced the air flow meter and air box base. It took a little pressure and wiggling to get the air flow meter over the new gasket. This is the hardest part of the operation. Once they were seated I replaced the two 13 mm bolts, air filter, air box cover, and air tubes.
The gasket cost $8.50 and took about 1 hour to replace.
Copyright 2000, George A Suennen