running lean

[clutch187]

Hello my car seems to run and drives fine, but the spark plugs are telling me otherwise and car has no power. the insulators are chalky white like they were when brand new. ive replaced the fuel pump cause it was getting really weak, replace the fuel filter with a new z32 one, fixed the wiring to the knock sensor cause ecu was always saying it was bad, fixed all exhaust leaks and fixed all vac leaks i could find (starting fluid method). checked and redid timing numerous times. i can't figure it out as to why my cars running lean. can anyone give me and advise on what to check next or how to fix my problem. the car in a 92 nissan 240sx s spd with a ka24de.