AFR fluctuations

[B Cowdrey]

Can someone take a look at my AFR fluctuations im getting around the 10-13sec and 16-18sec mark on this log file. Its N/A B18c and am getting inconsistent AFR fluctuations under load between 3 and 5K RPM. Does this look like a wide band sensor malfunction? Its annoying as  I have a a warning light setup to illuminate if AFRs go lean at WOT and its consistently flashing at me around this area.

Log 2015-12-13 2;57;09 pm AFR fluctuation.llg

[Scott]

The lambda reading is certainly up and down a lot in that part of the log. Your injection pulse-width, manifold pressure, and ignition timing are all pretty consistent, so it possibly could be a faulty wideband sensor or controller. Is your lambda signal coming into the ECU over CAN or an AN Volt channel? 

[B Cowdrey]

AN volt channel, The more I think about it the more I think it must be a sensor issue since it doesn't occur every time.

[Scott]

It sure could be. If you want to post up your base-map I can test it on an engine simulator to see if I can create the fault.

Check the wiring for your wideband controller/amplifier to make sure the power and ground are good.

[B Cowdrey]

I dont want to be too much trouble. It seems to run fine

honda civic B18c mod NZEFI 27-6-2015.pclr

[Scott]

I can't see anything in the base-map causing the problem. If you set AN Volt 3 to 'Voltage -0-5V' and look at the analog tab of the runtime values window (F12 key) you will be able to see if the actual voltage coming into the ECU from the Wideband controller is fluctuating.