IMHO from you symptoms above, and the original symptom of barely running:
- Vacuum leak
- Plugged fuel delivery, possibly due to trash in the new fuel (sometimes happens right after a fresh load of uel to the station stirs up crud in the underground tanks): take off the fuel filter and see if you can easily blow through it in the normal direction; be careful to not ingest any fuel
Yes, I would be getting the old fuel out but it there is trash in the tank now, it has to bee pulled to get it out