My problem worsen last month and oil began to increase in quantity. I read in posts here that this is the problem of 4jx1 engines. I went to have the injector checked and the shop said that I need to replace the injectors because the seals are leaking. I was able to buy 1 set of injectors and have them replaced and right now it is working well. The engine starts at once and engine response increased. Just posting the solution to my long time problem which I just recently solved.