Engines pops/misfires low throttle worse at startup.

Bought an 88 with 38,000 original. 2.8L...was misfirings and I could see the wires arcing. Changed wires,plugs,cap and rotor. A little better but still bad. Bench checked Module at Napa, ck good, dicovered pick up coil leads cooroded and cleaned and reinstalled with new connector same pick up coil. Can a mass air flow ensor cause the engine to misfire/pop? no serious back fires. Ran Sea Foam to fuel and drove 500 miles. Still the same. This car was driven less than 2000 miles a year and sat for the last three years. ????? Can you help?

Mike