Author Topic: Fuel and Fuel Management....  (Read 917 times)

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chitchc2

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Fuel and Fuel Management....
« on: March 26, 2011, 07:54:58 AM »
As a result of my engine modifications that can be found in the projects section I now have a lean condition code. I don't much care about the code TBH but I do care about the lean condition. The fuel is only lean (16:1 range) low in the RPM range and I haven't checked yet but I bet it's only while in closed loop. Higher in the RPM range when I'm positive it's in open loop the fuel mix is around 13:1 which is about where I want it. Prior to modifications the mix was very fat in open loop (12:1 range).

Question/Topics
1) Sharp has offered a lot of useful injector information but my concern is increasing flow will fix the bottom end but make the top end fat again.
2) Does anyone else have any AFR to RPM information from a personal data logger or after market fuel manager?

Offline sharpxmen

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Re: Fuel and Fuel Management....
« Reply #1 on: March 26, 2011, 08:58:00 AM »
As a result of my engine modifications that can be found in the projects section I now have a lean condition code. I don't much care about the code TBH but I do care about the lean condition. The fuel is only lean (16:1 range) low in the RPM range and I haven't checked yet but I bet it's only while in closed loop. Higher in the RPM range when I'm positive it's in open loop the fuel mix is around 13:1 which is about where I want it. Prior to modifications the mix was very fat in open loop (12:1 range).

Question/Topics
1) Sharp has offered a lot of useful injector information but my concern is increasing flow will fix the bottom end but make the top end fat again.
2) Does anyone else have any AFR to RPM information from a personal data logger or after market fuel manager?

in closed loop the AFR should always be 14.7, what you probaly get as in 16 AFR at low rpm is probably open loop due to better VE at low rpm so that results in more air (when you suddenly floor the pedal you will go in open loop for a bit until the rpm stabilizes if you're not staying at wot), you could use an a/m programmable MAP to correct that if you're 100% that mid to high rpm AFR is where you want it to be, otherwise increasing the injector size will lower the AFR in both instances (low and high rpm in open loop).
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
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Offline sharpxmen

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Re: Fuel and Fuel Management....
« Reply #2 on: March 26, 2011, 10:42:11 AM »
2) Does anyone else have any AFR to RPM information from a personal data logger or after market fuel manager?

forgot to mention, a piggyback would be 3 dimensional (that's what you want): MAP correction in relation to actual MAP and RPM, problem is that at low rpm you will be close to 0 vac reading (or ambient atmospheric pressure) so won't be much you can add - there can be a increase but just slightly as your map would already be reading close to the end of the range.

Were they able to give you the AFR readings on the dyno run?
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

Offline FourbangerYJ

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Re: Fuel and Fuel Management....
« Reply #3 on: March 26, 2011, 11:01:01 AM »
http://www.summitracing.com/parts/ACC-150126/

Would these be to much injector at 26#. Looks to have the CV-1 connector.
Scott~

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