2002 Ranger 3.0 Wont start-then starts 6 hours later

So this seems to happen after the truck has warmed and had a chance to heat soak, then returns to normal after cooling off? Have you checked for spark when the problem is present? Could be a bad ignitor module in the distributor if your truck has one. One of the failure modes is just as my first line indicates.

I had a similar problem in my 92 f 150 and it turned out to be a problem in the fuse box in the engine bay. There was a diode that wasn't making good connection, it just needed cleaned and stuff.

I had a similar problem in my 92 f 150 and it turned out to be a problem in the fuse box in the engine bay. There was a diode that wasn't making good connection, it just needed cleaned and stuff.

The first time it happend,it was about 90 degrees outside,yesterday it was about 60,but the truck had been sitting for 2 or 3 days.I didnt check for spark,but it has distributorless ignition,I was also thinking vapor lock,but it isnt carbureted. It's a pain when it happens but at least it started again i guess. Of course,as is always the case it's just out of the extended warranty.

I had the same problem with my 2002 Fx4. Finally a yellow check engine light came on. The code said it was low coolant temperature. We replaced the thermostat and it has never bothered again.

Coil packs - $5 inline tester lights up if there's spark going to the plugs. There's something like it for checking signal to the injectors, and a valve stem thing (bleeder) on the fuel rail that'll let pressurized gas out if it's present. The fuel pump can be heard clicking inside the tank as can the injectors with a screwdriver listening through the handle.