1993 Ford Aerostar Misfire

A badly needed tune-up could cause your problem to include be below

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)

Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:

Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires

The fuses that powers the radio is the fuse no.8 15amp and fuse no. 11 15amp.

Thank you for your reply to my question. I think you are right...a full tune up is probably in order. What a nightmare reaching those plugs and plug wires. What's the secret to changing plugs and wires?

Jack the vehicle up and let it sit on stands. Make sure you have Ford or Autolite double platinum plugs plus some copper anti-seize (for the plug threads). It's a good idea to change the cable at this time too. (Use Motorcraft or Autolite only). Remove the front wheels and the well cover (located inside your 'star; between the driver & pasenger seat, right on the floor, below the radio). You sgould have enough room to change the all plugs. Access from underneath

rather than removing the wheel, iner cover etc. on my 4.0L I removed the altermator and throtle cover and accessed the passenger side plugs and wires. Replacing wires one at a time is a real time-saver