Update:
I refilled worth P500 Sea Oil (last fill up was Phoenix) and hinaluan ko ng 50ml 2T. Parang medyo mausok pa rin at sudden acceleration, although I might be just paranoid. I havent had a chance to drive it past 100kph. What I did was put the gear in neutral, and rev the engine up to 3500 rpm (with AC and all the lights on). No hesitation naman, although mausok talaga ( I guess eto naman talaga ang behavior ng diesel).

Question: If there is a problem with my injectors, would I still be able to rev my engine that high, although in neutral?

Im crossing my fingers that I just had a bad fuel problem. Will still schedule TBelt replacement asap.