1994 Ford Ranger does not start (on occasion)

My 1994 Ranger turns over but does not start on occasion. The occasion is whenever I need it to and not when I bring it in. Shops just can not get it to not start when I bring (or tow) it in. When it starts it runs great! I have no check engine light. Any ideas?

When it dies Get a spark checker that goes between plug and plug wire, you see spark everytime plug fires.
If you get spark you take spray starting fuild with straw and loosen air intake closest to motor, give it a shot and if it starts for a moment you know it fuel trouble and can go from there.

Good tips, I’ll give a try. Thanks!