stevo original

i have a 04 yukon and i am having the same exact issues. it started out dying while pulling a trailer when it was hot outside, then started stalling out if it was hot out. then it will start right up after i turn the key to on then off a few times, so i replaced the mass airflow sensor, the fuel pump, fuel filter,and tomorrow will be replacing the crankshaft position sensor . im testing the new one prior to installing it since ive read a lot of stories where the new part was defective to start with.. so i will let ya know how it goes because ive had at least 4 different mechanics scratching their heads and nobody has been able to fix it yet..if this doesnt work i guess im out of ideas.