2001 yukon xl fuel issues
 

i took a wrecked 2001 yuk xl hit in the side i took the whole wiring steering column motor trans without cutting anything and put it in a 78 2500 chevy truck it has unbel power and never fails to start and if you put your foot in it she runs perfect but if you drive at a steady pace after amile it starts to run like you put the choke on if it had a carb you can turn the key off while your driving and turn it back on and it runs perfect for about another mile it also does this at an idle and you can turn it off start back up it will run fine for a few moments its has the oem tank mounted in the bed with oem hoses and it ran perfect in the xl before i changed it and there are no trouble codes pppplllleeeaaassseee help