I have a 1998 Toyota Land Cruiser with the following issues and am hoping someone ha sthe answer or possible solution. The truck is from Washington, but travelled to California this week. Once it got into hot weather 108 degrees, the vehicles starts sputtering under load. At idle it runs smooth. It will not get above 40-45 m.p.h. when this happens. New plugs, new wires, new fuel filter, new fuel pump, newer charcoal canister. I am losing my mind here. Any help would be appreciated.