will a engine for sure start on starting fluid?

If it won't even attempt to run on starter fluid then one can assume the timing is way off. Run a compression test.

I don't know which engine you have, but I'll assume it has a timing belt rather than a chain. That 20 year old timing belt probably skipped a notch or three. You're lucky if it didn't damage the engine..... If it has a chain, the tensioner probably went bad.

Sounds like the truck is treating you the way you treat it .

If you know you have spark but it won't run on the starting fluid it's either flooded with too much gasoline or you have no compression because the timing chain or belt has jumped. Hold the accelerator pedal to the floor while cranking the engine. This will put the computer in clear flood mode. If it still won't run do a compression test. If all cylinders test very low or zero it's jumped timing. Hope that helps! Jim