Power FC engine goes full lean when i try and pull out fuel
01-01-06, 03:10 PM
#1
engine goes full lean when i try and pull out fuel
Finally able to sit down and do some boost tuning. Whenver I try and pull out fuel in rich areas the car falls on its face and I get a full lean reading. So the only options for fuel seem to be only rich or no fuel at all. I'm running 850 prmaries and 1600 secondaries with the stock twins set for non-seq. Running -.53 timing on the injectors and I can get the idle to run a solid 14:1.
01-02-06, 12:46 AM
#3
lc1 wideband using the an1 input delta an1-an2. I'm making adjustments in the inj correction field. I'm making small changes as I go. It seems there is a threshold where im either rich or just not putting in any fuel at all, right as soon as I hit any P10 field and beyond the car just ***** on itself. If I use the basemap values that came with the PFC everything runs fine, but im running slightly rich in the boosted areas and am in the fine tuning process. I've made corrections to page 5 that correspond to my setup and everything is just great until I start to subtract fuel in the correction map. I do not have this problem in vacuum, I have my idle running the a/f that I want and I can subtract fuel all I want in vacuum without falling off the cliff that boost seems to be giving me.
Last edited by Aeka GSR; 01-02-06 at 12:49 AM.
01-02-06, 09:55 AM
#4
Send me a PM so we can exchange emails, I'd be happy to look at your .dat file and a log or two to help you figure this out.
When I use the recalc function to set all the INJ map values to 1.000, it is easy to decrease fuel by cell and we usually get a fairly good response in the AFRs. Every 1 percent taken out is about a 0.1 AFR reduction, it does take many adjustments to get it close as AFRs jump around a little from run to run and with the PFC interpolating between rows and columns it's hard to get it spot on in multiple runs and adjustments let alone a single run and adjustment.
It usually takes me about two hours to get a couple of boost rows close to my AFR target. The first few runs involve timing adjustments to avoid knock and learn the car's personality. Then it's run after run to get the AFR's close, and typically a few timing changes along the way when knock is high in a cell, often around peak torque or in low boost areas as the PFC maps have a lot of advance in low boost. But whenever I make changes across a p-row, meaning I set the INJ map values to say 0.97 for a few cells, perhaps 0.99 to another two cells, and 1.02 to a slight lean cell or two the net effect for the next logged run is closer to my AFR target. Maybe not ever cell but overall I am closer each time until I get real close. Then to get it spot on I start looking at the base map values to smooth out the fuel transition from cell to cell or I may never get a near perfectly predictable AFR across the entire map. This takes several days of tuning to get each p-row of boost area tuned, you wind up tuning more than driving to get this nutty but when finished you know it's spot on.
I try not to make changes greater than 5% unless I'm way off like richer than 10 AFR. Then I will take out like 5% across a large part of the map until I et AFRs within the useable range of the wideband, then make 5% or less changes as I step toward my AFR targets. You know you are close when all cell adjustments are all around one percent or less.
When I use the recalc function to set all the INJ map values to 1.000, it is easy to decrease fuel by cell and we usually get a fairly good response in the AFRs. Every 1 percent taken out is about a 0.1 AFR reduction, it does take many adjustments to get it close as AFRs jump around a little from run to run and with the PFC interpolating between rows and columns it's hard to get it spot on in multiple runs and adjustments let alone a single run and adjustment.
It usually takes me about two hours to get a couple of boost rows close to my AFR target. The first few runs involve timing adjustments to avoid knock and learn the car's personality. Then it's run after run to get the AFR's close, and typically a few timing changes along the way when knock is high in a cell, often around peak torque or in low boost areas as the PFC maps have a lot of advance in low boost. But whenever I make changes across a p-row, meaning I set the INJ map values to say 0.97 for a few cells, perhaps 0.99 to another two cells, and 1.02 to a slight lean cell or two the net effect for the next logged run is closer to my AFR target. Maybe not ever cell but overall I am closer each time until I get real close. Then to get it spot on I start looking at the base map values to smooth out the fuel transition from cell to cell or I may never get a near perfectly predictable AFR across the entire map. This takes several days of tuning to get each p-row of boost area tuned, you wind up tuning more than driving to get this nutty but when finished you know it's spot on.
I try not to make changes greater than 5% unless I'm way off like richer than 10 AFR. Then I will take out like 5% across a large part of the map until I et AFRs within the useable range of the wideband, then make 5% or less changes as I step toward my AFR targets. You know you are close when all cell adjustments are all around one percent or less.
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