I have a '91 DeVille that starts to hesitate when it's hot. Feels like its not getting fuel, but when I put it in park and rev it it's fine. Could this be thottle or cam position sensor. Thanks for any help.

 

Some info that I didn't include above is that it has 4.9L 160k miles and cam position sensor was replaced about a year ago.

 

It only dose when it's hot?
How hot? As soon as it gets hot or hot been running for a while hot? Do you get any codes?
My first look would be a vacuum leaks look at the Vacuum lines and if it only happens hot look for leaks around the intake.
Mine had a similar problem turned out to be the fuel injectors.