O2s read max lean after CL kicks in??

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Fender2k5
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Joined: Sat Apr 14, 2018 3:39 pm

O2s read max lean after CL kicks in??

Post by Fender2k5 » Sat Apr 14, 2018 3:45 pm

Im working on a 2004 mach 1 that starts and runs great in open loop but as soon a CL kicks it jus richens up til it stops at ~30%... somes times i can rev it up and get it to start correcting back to 14.7, and sometimes jus the passenger side reads lean. It runs great and Afr is good when i force open loop. I checked the o2 extension harness and wires to the ecu. Everythings good. Any ideas?

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skunk
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Re: O2s read max lean after CL kicks in??

Post by skunk » Sat Apr 14, 2018 4:45 pm

CL sounds like it's correcting for changes you made to your tune based on your WB feedback. Are you saying the WB is reporting rich (~11.3) or Lambse is commanding rich (~11.3)? Your passenger side sometimes lean comment has me confused.

Under normal start up...you will be in OL and getting enrichment. If you have tuned out this enrichment the ECU will likely start dumping fuel to force the HEGOs to switch as soon as it enters CL.

Have you verified the Hegos are actually switching?

You may also need to look at your WB setup. Depending on what software your tuning and logging with......your transfer function may need tweaking to compensate for voltage offset. If you unplug the sensor, the controller should put out a steady voltage and the guage will read a corresponding AFR. Hopefully whatever your logging with allows you adjust the transfer function and then you can get your log to match the guage.

John
1987 Turbocoupe.
A3M1/A9L, BE/EA, Tweecer RT.
306,Single Turbo, Ported E7's, Ported Stock Intake, 42lb Matched Green Tops, PMAS 3" Blow-Thru Protube (42# supercharger calibrated),T5z, 3.73 gears
..... Nothin Fancy.......Just something to keep me from the honey-do list.........

Fender2k5
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Joined: Sat Apr 14, 2018 3:39 pm

Re: O2s read max lean after CL kicks in??

Post by Fender2k5 » Sat Apr 14, 2018 5:22 pm

When i tuned it in openloop i had a daytona Wb in it, and the software( binary editor) matched the reading. Switched to closed loop and the passenger side commanded lambse would say 10.98 while the driverside would change under and over ~14.7. It came back on while driving. Then the next day both sides would ramp down from 14.7 to 10.98 right after CL kicked in hot or cold start . Stuck an lm2 WB in it and it ramps down from 14.7ish to 12:1. Seems like if you get it switch into OL with from tps volt it will go back to 14.7 when it settles down to idle, then ramp right down again

Chris Mureen
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Re: O2s read max lean after CL kicks in??

Post by Chris Mureen » Sun Apr 15, 2018 10:06 am

One suggestion that you might try is resetting the EEC. I've seen weird behavior before when the KAM gets corrupted. Not sure if you've tried that yet.

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