After the valve replacement everything was put back in and timed. The car is hard to start and ones started runs rough and runs on the rear 3 cylinders only. All the fronts are inactive. Fuel is okay checked injectors. coil resistance is okay although didn't check power. What could it be? Maybe switched cams exhaust and intake as I had trouble differentiating them? But the markings both lined up in either position even if the cams were switched. Could this be tha cause? Or bad ignitor? I didn't switch the harnesses yet. Please help.