High Fuel Trims, Running Lean, Loud Valvetrain

[t.mcginley.jr]

Hi everyone,

I just finished rebuilding my 01 Corolla's 1zz-fe engine and I'm having some problems. It started with misfire error codes: P0300, P0302, P0304. Replaced the upstream O2 sensor with an OEM Denso one and it took care of it. However, the fuel trims were always high. Only maybe a mile on the rebuild, I've now replaced the fuel injectors, pump, filter (strainer and actual filter), new OEM irridium plugs, etc. and the long-term fuel trim is still at 23% and goes up to 30% sometimes.

Check for vacuum leaks and didn't find any or hear anything, and hooked up a vacuum gauge and it pulls about 22 lbs of vacuum. Hooked up the scanner and the MAF sensor reads 0.3 lb/min which is normal (cleaned it anyway).

Here's a video of the engine running, mostly recorded for the audio:

https://www.dropbox.com/s/ioax0hsg3zi098c/VID_20140613_074144_397.mp4

Any ideas on what else to check??

 

[Scott O'Kashan]

Why were all those parts replaced?

 

[t.mcginley.jr]

The fuel filter and spark plugs were replaced just because it's at 185k miles. The upstream O2 was replaced because it wasn't reading correctly. The fuel pump and injectors were replaced because I thought they might be the problem, apparently not though. I'm just running out of ideas/possibilities... thinking about doing a leakdown test to check compression but it should be fine.

 

[Donabed Kopoian]

If you are getting a high fuel trim with misfire codes, then I would check the ignition circuit for shorts or frayed wiring. Check your misfire count as well.