I have a Convertible 89 GT 5-speed that won't start in hot weather. When I turn the key on the fuel pump will not run. I have replaced the fuel pump relay, ecm relay, had the ecm rebuilt, and replaced the module on the side of the distributor, all on the advice of different mechanics, nothing helped. It seems to be losing the ground when it gets hot. Has anyone else had this problem or have an idea what to look for? Any help will be greatly appreciated. Thanks.