Two weeks ago, my 98 voyager 3.0 engine wouldn't start on cold engine. 1/2 tank of gas. It cranked, but wouldn't start or even attempt to start. Same next day.

Two days later, it started without any problem!

Running fine since until yesterday!

After driving an hour, I stopped for 15 minutes. Same thing, but this time on a warm engine. Tried and tried, but it will not start.

Any ideas?