I have a 2008 F150 with 5.4. Truck was running fine. Had the oil changed on Thursday. Drove home and back to work on Friday and back home. Parked the truck and when I went to crank it Sunday it sounded like it was running on 4 cylinders. What could have happened? It shut off and will not crank now.

I should have said that most of the time the engine won’t start. It will turn over. Sometimes when I disconnect the battery and reset the pcu it will start and run fine for a few minutes and then start acting like it’s running on four cylinders and shut off again and not start back up. I have unplugged the vct’s and nothing changed. I am planning on changing the timing set but I was hoping for an easier fix. Thanks

I changed the fpdm it is new.