I have a 1988 T-Bird with the 3.8 liter v-6. Every so often, months apart, the car will refuse to start until many attempts are made. The car has always eventually started, and once it does, it runs normally for months before the problem occurs again. When the eingine finally does start, it runs smoothly as if nothing had happened.

 

Maybe try early maintenance like cleaning battery cables, changing the air filter and spark plugs (stock type in a set) and wires (stock type in a set) oil and filter and fuel filter. At 100,000 I'd also recommend a transmission filter and fluid change. These things help to keep the computer acting normally and keep the big garage bills away. When regularly serviced you usually know exactly what parts went bad without having to pick through the little annoyances of neglected/forgotten stuff.

 

Keep in mind to depressureize the fuel system before changing a fuel filter, though.