Hi, my Sentra B14 is acting up again. Mausok, maitim at amoy gas. Carbon fouled ang spark plugs, lahat. Ang mga nacheck na
1. Tested using ibang distributor, mausok pa din.
2. Bago ang air filter.
3. Bago ang fuel filter.
4. Napalitan ang spark plugs.
5. Adjusted ang idle screw adjust. Walang difference either lean or rich mausok pa din.
6. Okay daw ang fuel pressure.
7. Okay din daw ang fuel injectors, nagbu-burst ng gas, nag stop din. Wala din daw leak ang o-ring sa fuel injectors.
8. Scanned, according sa shop MAF sensor daw at IACV sensor
9. Tested using ibang IACV at MAF, mausok pa din.
10. Tried disconnecting yung front O2 sensor, walang difference.

What else can be causing the unburned fuel? Thanks for you help!