2010 Ford f150 5.4L 3v misfiring/ random misfire badly after engine timing chain,phasers and vct replacements. before replacement P0018 po345 and P0349 and P0022. After replacement p0022 and P0300 was there And running really ruff at idle. Before timing chain replacement it also had cylinder 5 misfire as well. I hooked up a scan tool and did a power balance test. Found out the graph goes crazy on cylinders 5,6,7,8 misfires. But when I rev it up no mis on any cylinders. Weird but anyone has any ideas whats going on? I don't believe timing is off cause no odd noises just a lot of missing. Everything is factory and it has 146k miles on it compression on whole engine 180psi I swapped coil and spark plugs and no change I can even Rev it up and doesn't sound bad just running ruff i didnt change timing i had all 3 marks lined up then removed everything then put it back where the marks were lined back up
Well since you swap the coils and stuff and it didn't change. You have some type of engine problem or wiring feeding the coils or fuel injectors. It's probably time to see a guy like me to do some tests with a bi-directional scan tool. But you could do a wet and dry compression test of the engine to see if the engine is physically wearing out inside first. That's a pretty easy test
