20V ST rich or lean? How to adjust AFM?
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TwentyValver
- Posts: 1
- Joined: Fri Mar 08, 2013 3:23 am
20V ST rich or lean? How to adjust AFM?
Good day fellow 4age-ers, i would just like to ask how to properly adjust my AFM, i feel that my mileage got low after somebody tightened/loosened the screw found in the afm, and now i dont know if im running rich or lean... Please help! Thanks in advance!
Re: 20V ST rich or lean? How to adjust AFM?
To properly determine if you are rich or lean, and where, you need a wideband O2 sensor.
You can either install it in the downtube of the header collector (reccommended) or at the exit of the tailpipe with a special clampon venturi rig. Response is slower there.
You can either install it in the downtube of the header collector (reccommended) or at the exit of the tailpipe with a special clampon venturi rig. Response is slower there.
"When the going gets, wierd, the Wierd turn Pro" -- Hunter S. Thompson
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yoshimitsuspeed
- Club4AG MASTER
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- Joined: Sun Jan 13, 2013 1:18 pm
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Re: 20V ST rich or lean? How to adjust AFM?
Yeah you definitely don't want to tamper with the AFM without being able to monitor AFRs. Who adjusted it and why?
If they just messed with the screw it should only mess with idle AFRs and it takes a ton before you go so far the O2 sensor can no longer compensate.
There should be some numbers near the screw and it is a code to tell you how far it's supposed to be unscrewed. I forget how to translate the code but there are threads on the subject somewhere on the MR2 boards.
If someone actually went under the cover and twisted the flap spring adjustment then you would definitely need a wideband to confirm it's functioning properly. Unless the person was smart and marked the original position. There is really no reason to tamper with these things until you get to advanced levels of tuning where you are really pushing the limits of the ECU.
If they just messed with the screw it should only mess with idle AFRs and it takes a ton before you go so far the O2 sensor can no longer compensate.
There should be some numbers near the screw and it is a code to tell you how far it's supposed to be unscrewed. I forget how to translate the code but there are threads on the subject somewhere on the MR2 boards.
If someone actually went under the cover and twisted the flap spring adjustment then you would definitely need a wideband to confirm it's functioning properly. Unless the person was smart and marked the original position. There is really no reason to tamper with these things until you get to advanced levels of tuning where you are really pushing the limits of the ECU.
