LTFT questiong ... come on in tuners!!!
When it goes from closed loop to open loop / PE mode (throttle maybe 70% open or more), if the LTFT's are negative they will go to zero. I.e. the PCM will stop subtracting fuel if it was doing so in closed loop mode right before it went to open loop. So in theory if LTFT's were slightly negative then it'll be slightly richer during PE, but you don't want it too rich.
Sorry to jump in here,but i am curious.
My LTFT's read -12.50% at cruising speeds and anything over 25% throttle the trims just go to 0.00
No matter if it is part throttle/half throttle or WOT. they just stay the same.
The O2 readings stay around 780-850 while cruising and high 800's to mid 900's WOT depending on rpm.
I was checking these things so i could get a tune from Predator and now that i see these things i wonder what is going on.
NOT trying to hyjack your thread,just curious about this topic.
Hooker lt,ory pipe,
!egr!
!a.i.r.!
gmas,lid,k&n,160stat,NGK TR6's,MSD wires. Everything else is stock.
Predator programmer.
Dave
My LTFT's read -12.50% at cruising speeds and anything over 25% throttle the trims just go to 0.00
No matter if it is part throttle/half throttle or WOT. they just stay the same.
The O2 readings stay around 780-850 while cruising and high 800's to mid 900's WOT depending on rpm.
I was checking these things so i could get a tune from Predator and now that i see these things i wonder what is going on.
NOT trying to hyjack your thread,just curious about this topic.
Hooker lt,ory pipe,
!egr!
!a.i.r.!
gmas,lid,k&n,160stat,NGK TR6's,MSD wires. Everything else is stock.
Predator programmer.
Dave
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I see large negatives in the idle cells, you may want to
just ignore this (cell 0). On late Camaros there are only
8 trim cells, effectively, due to where the cell boundaries
w/ RPM are set; the low end cells have to "cover"
everything from off-idle to cruise and can get a bit of
PE into them so they are not stable or especially sane.
I would look more at cells 5, 8, 9, 12 & 13, don't worry
about 0, 1 and 4 as these are low-flow and not so
relevant to WOT. As long as they're negative, forget
about them.
just ignore this (cell 0). On late Camaros there are only
8 trim cells, effectively, due to where the cell boundaries
w/ RPM are set; the low end cells have to "cover"
everything from off-idle to cruise and can get a bit of
PE into them so they are not stable or especially sane.
I would look more at cells 5, 8, 9, 12 & 13, don't worry
about 0, 1 and 4 as these are low-flow and not so
relevant to WOT. As long as they're negative, forget
about them.
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Originally Posted by jimmyblue
I see large negatives in the idle cells, you may want to
just ignore this (cell 0). On late Camaros there are only
8 trim cells, effectively, due to where the cell boundaries
w/ RPM are set; the low end cells have to "cover"
everything from off-idle to cruise and can get a bit of
PE into them so they are not stable or especially sane.
I would look more at cells 5, 8, 9, 12 & 13, don't worry
about 0, 1 and 4 as these are low-flow and not so
relevant to WOT. As long as they're negative, forget
about them.
just ignore this (cell 0). On late Camaros there are only
8 trim cells, effectively, due to where the cell boundaries
w/ RPM are set; the low end cells have to "cover"
everything from off-idle to cruise and can get a bit of
PE into them so they are not stable or especially sane.
I would look more at cells 5, 8, 9, 12 & 13, don't worry
about 0, 1 and 4 as these are low-flow and not so
relevant to WOT. As long as they're negative, forget
about them.
Sorry i am of no help (technically) But i know my car surges at idle in gear only. And falls flat on it's face above 5500 RPM . I set shift points to 6300 and it popped and felt like valve float to me. Then pulled real hard after each shift like normal.
It still is not happy with 6100 1/2 shift-5900 2/3 shift ,power just bogs down . N/A and on spray.
Soliari- thanks for not getting mad at me posting in your thread.
Dave
