If your ignition electrics are all new (my guess was going to be "coils") then the only other thing it could be is "petrol".
Disconnect the fuel hose to the injector and stick it in a small container. Is there a healthy looking fuel flow when you crank the engine over (try this with a cold engine)?
If you're not getting much flow, you may have to pull out the fuel pump and see what's up with it.
The beast ought to have a fuel filter somewhere too (possibly in the tank). When did you last clean/change it?
It might also be worth taking out the injector and having a look to see if there's any obvious blockage/dirt on it. They're tricky to clean off the car (you need a rig) but a squirt of carb cleaner might help it.
Ralf S.