Mazda truck 1995 wont start when out in the sun!

My 1995 mazda B2300 won’t start when it has been parked out in the sun. Once it cools off at night or if i park it in the shade, it starts fine. It seems like it is not getting gas. Per mechanics suggestions I have changed the started, the battery, full tune up and nothing has worked. Others have suggested that this is a faulty model in relation to the fuel pump or fuel lines being in the gas tank? HELP

You need to confirm what is not working. Fuel and fuel pressure can be checked. If the truck has no fuel pressure at start-up after sitting in the sun, then you found the culprit and the parts you threw at it have nothing to do with it. The fuel pump, relay, and ECM signal all must be tested.

If, however, the starter refuses to turn the engine, replacing the starter and battery makes sense. Just replacing them is, again, just throwing parts at it, since they can both be tested. And there is much more to the starter circuit than a battery and starter. You have the ignition switch, relays, wiring and cables that could all be suspect. And, you can jump the starter solenoid in-place to confirm the battery and starter are OK and the problem lies between the ignition switch and starter. Take a piece of wire, 14 ga. or larger, add a spade connector to one end. Unplug the signal wire, and replace with this jumper. Touch the other bare end to the positive on the battery. If the starter works, then problem is between the ignition switch and starter signal input.