2001 Toytoa 4Runner Stalls

[exbanker]

My 2001 Toyota 4runner has had occasional issues with stalling. It seems to hapen when it rains or snows. The check engine light has never come on. We have replaced the fuel filter, air filter and cleaned the mass air flow sensor. Took it to the dealership, they couldn't get any codes and cleaned the mass air flow filter again. We have had rain and it stalling again. When it stalls it restarts itself when you shift from park through neutral and has tried to start itself again in reverse. It makes a whiny noise like the starter is trying to re engage. The mechanic doesn't think it is the starter or starter relay. Any ideas or suggestions would be greatly appreciated!