Car will not pull hills

Cold be a faulty coil pack but check for codes first as it should show up. You still shold check feul pressure as that can have a lot to do with this running. As well as the white smoke telling me it may be leaking coolant through one of the gaskets into cylinders. Quit trying the shotgun approach by replacing parts an dactually do some tests on this to give you a better idea of what is wrong with it. Also check vacuum at intake if 15" or below suspect plugged exhaust autoparts rent the gauge you just have to take it at the fuel rail.

I would start by connecting a fuel pressure gauge to check the pressure. It should remain up after the engine has been off for days, but it's pretty common for it to drop to 0 pounds. If it does, watch how strongly it comes back up when you turn on the ignition switch. My suspicion is the pump became overheated and it warped causing it to run erratically or too slowly. Fuel in the tank cools the pump. The running problems you described are experienced by a lot of GM owners after running out of gas, and running the pump dry is the only thing all those cars have in common.

Overheated pumps are such a concern on Fords that their fuel gauges are calibrated to read "empty" when there's still about seven gallons in the tank. I know from experimenting with my old Grand Caravan that normal fuel pressure is around 45 - 50 psi, and it will still run fine down to 20 psi. A lot of GM engines will not start or will run poorly when the fuel pressure is just a few pounds low. That is unexpected so it's easily overlooked when looking for the causes of no-starts and hesitation complaints.