I have a 2003 Volvo S80 T6. It is misfiring pretty badly. What I've done so far is verify that there is absolutely no vacuum leaks, smoke tests and starting fluid test. I have swapped around and tested coils which all work and I have checked it. I know the plugs are all new OEM plugs. However, where I have the problem is when I was checking the coils, I unplugged one at a time to find the one(s) that doesn't make a difference unplugged. Cylinder 1-3 makes absolutely no difference when each of them are unplugged but 4-6 on the other hand all make a difference when you unplug them. It's got the check engine lights for those cylinders and a multiple misfire code. I'm pretty stumped, I don't know if there is 1 plug for each half of the engine or if 1 plug services all 6. that go to the fuel injectors or something? Just don't understand why the coils all test good but the 1-3 cylinders don't change a bit when coils are unplugged. All coils are sparking so its gotta be fuel related in the first 3 cylinders. Any help or advice would be greatly appreciated. The turbo works and spools as well. You can feel the boost still when you drive it.

 

Can you take out fuel rail with injectors and try to crank the engine to see if injectors spray? Or test injector connector with multimeter.

 

I didn't think about taking the fuel rail off. That a pretty good idea. I wont make a huge mess will I lol? I will try that. The injectors work, I swapped one half with the working half and have the same issues in the same cylinders. I will probably try that now.

 

Im gonna check the plugs and coils again because I took the fuel rail off and all of them were squirting the same amount. So we have gas, and I was pretty damn sure I had spark, but Im gonna check that again.