Q.advice on dying pumpkin plants
This year, I decided to plant 4 pumpkin plants. They grew fine, and then they started dying slowly. Now they are almost all the way dead. Any advice to why they would be dying?

It could be a number of things effecting your plants; environmental, insects, fungus or viruses with the plant.
Here are some links that will help you pinpoint the issues.
https://www.gardeningknowhow.com/edible/vegetables/pumpkin/pumpkin-growing.htm
https://www.gardeningknowhow.com/edible/vegetables/squash/signs-and-treatments-of-squash-wilt.htm
https://www.gardeningknowhow.com/edible/vegetables/squash/mosaic-on-squash.htm
https://www.gardeningknowhow.com/edible/vegetables/squash/why-squash-leaves-turn-yellow.htm
https://www.gardeningknowhow.com/edible/vegetables/squash/squash-pumpkin-rot-disease.htm