2002 Chevrolet Express Van 5.7 1500 has no power going up hill
 

2002 Chevrolet Express Van 5.7 1500 has little to no power going up hill it goes in to passing gear but it just revs up and drop power real fast?

Does it also do that when you press the pedal down more than say halfway on flat roads? If so, its the fuel filter clogged. It will run fine, but under load it will not allow enough fuel volume.....Its like having no secondaries on a carb.....once you go to far on the throttle it bogs because too much air not enough fuel.......
If that is not it, then have you had it checked for codes?

Yes it does do the samething on a flat road. Would this cause it not to start also? Yes I did scan it I got codes 102 443 and 449. I replaced MAF sensor yesterday.

Okay. the other 2 codes are the Evaporative emission control system codes.....Google them and you will find some fixes.....

A clogged fuel filter should still allow starting, unless its now fully clogged......change it to be sure....

Replaced fuel filter. Still will not start on its own. And still no power when pressing on pedal about half way. But will run and idle fine I just have to build up speed to make it up even a small hill or go about 30mph. And spray starter fluid to start?????

https://www.obd-codes.com/p0449

https://www.obd-codes.com/p0443

....."There may be no drivability problems at all. But, it's also possible to have a lean condition or a rough running engine if the purge valve is stuck open....."

Read more at: https://www.obd-codes.com/p0443