Alfa Romeo Repair: Misses when warmed up, air flow meter, spark plug wires

Question
I have a 1987 Graduate that has been running great for the last 6 years.  Your recently helped me with a cold start problem and I want to thank you, the wires on the thermo switch were reversed.  The latest ailment, which has been persistent for about 2 months, is that the car has a miss only when warm.  I have replaced the vacuum hoses, plugs (bosch platinum 4s, cap, rotor and spark plug wires.  I emptied a canister of injector cleaner the other day but the problem still persists.    The car runs great until it warms up.  The miss doesn't seem to affect the power or speed of the car and seems to be prevalent at around 3000-3300 rpm and when under a load, like climbing a hill.  The nearest alfa shop is about 15 miles away and I'm about to take it in.  Any clues as to what this could be?

Answer
It is a lean miss. You can try advancing the ignition timing to 6btdc. But, another thing to do is pull the black cap on top of the air flow meter and look for wear on the copper printed circuit about one third of the way up. If no wear is visible then loosen the spring tension about 3 or 4 notches.
Direct a hair dryer at the open space just enough to have warm air when you reinstall the plastic cap. Seal it with rtv black.