Since my post last year, I've had to replace 4 atomizers in Hinos. All of them were P2436. As greasytshirt states, when you see P2436, replace the atomizer. I was interested to learn what triggers turn this fault on, but it's futile. Just replace it.
As for P0087, it means fuel rail pressure is low. If you graph target and actual fuel rail pressure, you'll see that under heavy and sustained load, the actual pressure won't be able to keep up with the target pressure. I'd start with the replacing the fuel filter. Graph it again to see target and actual are the same. Then move on down the line, which I believe would be the SCV (suction control valve) attached to the lift pump. The lift pump is attached to the front of the injection pump. I can't think of a way to test the SCV other than swapping it with a known good one. Maybe before you spend $ on an SCV, remove the banjo bolts for the hard lines that go into the injection pump because some of them have screens inside the banjo bolts. A couple months ago, I encountered this problem. Customer had been getting P0087 for months. Finally, truck would only idle. It wouldn't rev past 1200 RPM. The fuel filter was horrible. After we replaced the filter, it ran fine until you were under heavy load for more than a few seconds. It wasn't hitting target pressure on sustained load. Replaced the SCV with a known good one, no change. We were removing the lines on the injection pump (because were were going to replace the pump) when we noticed a screen inside one of the banjo bolts was full of junk. Cleaned out the screen, put it all back together and problem fixed. Injection pump is in such a stupid place!