Ford - Explorer :: 1998 V8 Suddenly Refuses To Start Up After Short Stop In Hot Weather

I have a 5.0 Explorer 1998 and it has a problem for which I cannot find a definite solution, everyone says a different thing. The problem is that when the weather is hot, sometimes the engine does a strange thing. You ride the car for some time, especially if you do it on a high speed so the engine is really hot (but no overheating symptoms) - and then you kill the engine and leave it for a few minutes - to walk into a store, let's say.

After that you attempt to start the engine... sometimes it starts, but there were several times when it refused to catch, it cranks, at first tries to start, but stalls... then it just cranks without even attempting to start. And I had one occasion when it stopped working right in the middle of the road while crawling in traffic, but it was really HOT outside. Luckily, all other cases were in our town, so I could at least walk home. So, the problem seems to overheating of something, as in normal or cold weather it never happens. And every time, after the car is left to stay in place for some time, an hour or more, cannot say exactly - it starts perfectly!

I am really tried of this and want to eliminate the reason. But I am hearing so many different opinions about this problem. I thought that it could be the overheating of the fuel pump. But then it would stop working while moving, not after you shut the engine off and the pump cannot be still working and overheating. The only place where the heat can build up when you stop and turn the engine off is under the hood, as the fan stops, the coolant pump stops and the air isn't blowing as the car isn't moving. But the pump is in the tank! And I never ride on empty fuel tank, I always keep some level, lately I tried to keep it even higher, but yesterday it refused to start when the tank was almost half-full. Also, if it was just dying - a dying fuel pump gives certain symptoms like slow acceleration, engine shaking and trying to stall when you press the pedal, sudden stalling, uneven idling etc. In this case, nothing like this. The car's behavior is absolutely normal, acceleration good, normal idle. It happens ONLY under certain conditions, involving heat.

Other people say that it can be due to low pressure in the fuel ramp and the gasoline is starting to boil at some moment, when the temperature under the hood rises to a certain point. As a reason they name the pump (but as I said, I doubt it) or the fuel pressure control valve - don't know its exact name, it's a valve which maintains a certain pressure in the fuel ramp and releases excessive pressure by returning some fuel to the tank. However, when this valve gets stuck and doesn't maintain pressure, it mostly influences the cold start, as the fuel pressure drops and you have to crank for a long time while the pump is building the pressure again. But my car has never had any problems with the cold start, it's always instantaneous. Also, when this problem occurs and you start the engine after it cools down, it catches instantly which means THERE IS pressure in the ramp. So I don't believe in low pressure, gasoline boiling and resulting vapor jams.

And finally, I read that it may be caused by defective/dying engine temperature or crankshaft position sensors. As for the temp sensor, I will replace it tomorrow anyway. I am also thinking of having a look at the crankshaft sensor, where it's located on 5.0 V8?