1983 Toyota Supra Engine dies when gas pedal is depressed

My 1983 supra (2.8 L inline 6) would die if the gas pedal is quickly depressed. Once the engine stops, it cannot be started again until some later time like the next day.

At first, I thought the engine is not getting enough fuel because dirty fuel filter. I replaced the fuel filter and that did not solve the problem. Next, I changed the fuel pump (brand new) but the same problem still exists.

After the engine stalled, I try to restart but without success. Next, I removed the spark plug and noticed that it is wet with gasoline. It looks like the fuel injector spays too much fuel onto the spark plug. I also checked to see if the spark plug is putting out the spark. The cap and rotor were damage with burn mark. I have replaced the cap, rotor and spark plugs. The problem is still there.

Next, I want to check if the air flow meter is working properly. What is the best way to test the AFM (vane type)?