Does anyone have any idea why a Toyota Previa 1991 would have problems with the engine turning back on. Currently will not turn back on for several hours. Try sooner and it smells like raw gas. has new catalytic converter, new wires, new rotor, new fuel pump, new coil and wire, the gas rail tests ourt good for pressure. . THe MAF has been cleaned, new spark plugs, fuel injectors cleaned. Nothing has fixed the problem. Anyother suggestions???