I would suggest taking the cams out and the hydraulic lifters. Get one of those yellow rubber gloves on for cleaning and a small container filled with oil and soak the lifter, pressing the lifter in and out with the side hole of the lifter pointing upwards. At this point the top hole will be pointing to the side. Take in mind not to plug the hole at the top of the lifter when doing so. Keep squeezing until there are no more bubbles then pull the lifter out and shake it in your hand then put back in oil and squeeze. Repeat process until no more air bubbles. Then place lifters upwards for storage because this process is time consuming. This method I have been using for years and has worked great for me without out any lifter tap. Yes it does take a while to go through all of them but by squeezing them you can get a feel on which ones are "sticky" and need to be replaced. As far as everything else. Sounds like you need to also check the injectors and get them flowed. Checking the ohms only tells you if the electric coil inside the injector is good but is not good enough to tell weather or not an injector is flowing properly.