i have a 88 f-250 with a 460 this past week while funning the a/c the truck will surge like it has gained HP. then after a few times of doing that it will go back to running like it used to also a couple of mornings on the way to work the check engine light will flash but will not stay on. could it be a sensor or something clogged up?

 

does the idle rise when the A/C compressor cycles?

 

yes about 100 to 200 rpms