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Why is my VFR800 so pig rich at cruise? Map inside


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Hey guys. I have an 02 vfr800. Mods are 1999 catless header and gutted mufflers and flapper mod and K&N air filter. I have the power commander 5 installed with the 02 optimizers. As far as running it runs great so today I turned on my auto tune and just let it tune the cruise area from 5% to 20% throttle from 3750 to 5750. I am running the cozy may from here. My cruise AFRs are set to 13.5 to 13.6 in the cruise area. Just went for a ride to see what it would trim out at and was really surprised how much it pulled out to get it to the commanded fuel. I have looked at a ton of maps and they all look a ton richer than what mine trimmed out at in that area. I'm gunna try to post my map after the auto tune so you can see all the fuel it pulled in the cruise area. Just seem like the cozy may is way too rich or something for my bike. Look at my cruise area and you can see what the auto tune did to the cozy map. I knew it was rich because of how much soot was on my exhaust pipes but didn't expect to be this rich. What do you guys think of this? 

Modified Cozy djm map leaner cruise area.pvm

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OK, so the 01 & ALL later VFR800 have a closed loop mode with 2 x Narrow band O2 sensors in the exhaust. The ECU monitors 2 functions per O2 sensor, #1 Hot wire active, this is the 12v flow to the heater element in the sensor to get it to operating temperature from cold, this is what your O2 eliminators fake.  #2 is the lambda sensor reading which is only RICH or LEAN based on a target ideal AFR of 14.x-1, if lean ECU adds juice, if RICH is reduces it. This only happens at idle & steady throttle settings, i.e. cruise mode !

 

If you run O2 eliminators, then the ECU does NOT light the Fi light on the dash, as it assumes the sensor is in place as that line is drawing power & either it's not up to temp (initially) or faulty (the rest of the time) so it adds a fault code to the ECU fault log, but does NOT turn on the Fi error light on the dash. This is because all ECU systems use a base map to control the fuel injection, then trim the base map based on sensor inputs. Once lambda sensing is lost, it defaults to a RICH base map, as it has NO sensor info to verify the engines operation.

 

So if you replaced your headers with 98/99 Catless headers with no O2 lambda sensor ports & thus I assume added O2 eliminators (or resistors, same thing) then your bike will always be on the RICH map which will be approximately 12-1 AFR. So your auto tune will have to pull a lot back to get 13.6-1 AFR.

 

Depending on how a PC map was made, they rarely do a cruise setup, because DJ dyno's, can't maintain a constant load/speed state ! So they do a slow acceleration setup, which works well for setting EFI to match a predetermined AFR (usually 13.2-1 for DJ/PC) but the ECU uses constant throttle to activate the cruise mode closed loop, so it NEVER activates on a DJ setup 😞  I didn't use O2 eliminators on my Y2K model, when I had a PC3 on it, with a custom map it had perfect fuelling on the dyno, & when I was in cruise mode I got the benefit of closed loop, plus the benefit of better fueling when on the gas 🙂

 

I hope that explains it 🙂

 

Literally now YMMV  due to AFR ! 🙂

 

 

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Thanks alot. That explains alot. I didn't know the base map was set so rich from the factory. I will do a bit more riding and see how it seems to run at cruise. 

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