new pump and filter three days ago . does it if tank is ful or 1/2 .

Do you know where your fuel pressure regulator is?

What did you mean when you said the vacuum falls off?

when going up a hill the ac starts blowing out the defrost vents for windshield

Check into this next. The MAP sensor is very sensitive to vacuum problems.

https://www.gmforum.com/t280296/

Then read this

https://www.gmforum.com/t279320/


Have you had the car scanned for codes?

will check tomorrow

np

keep us in the loop.

cya later

map sensor looks bad . took it out all dirty. whats the part it snaps into allmost looks wet down inside of it hard to tell getting dark . will look better tomorrow

took map sensor out . the black on rubber seal it was black sealant why??????? got it all off looked down the hole of map sensor it looked wet. the cap for the pvc wasnt on all the way . got it off the pvc valve has oil all over it and inside to. wiped out as much as i could get out of the hole for the pcv . i have never had one of these a part before .should there be oil in there or did some body put it in there.??????????

is there a way for you to take photos of what your seeing?

The PCV (Positive Crankcase Ventilation) should have some oil in it.