In my tune I am trying to add fuel under light boost while cruising and small accelerations. But all the fuel i add the stft pull it right back out. How can i stop this from happening?
In my tune I am trying to add fuel under light boost while cruising and small accelerations. But all the fuel i add the stft pull it right back out. How can i stop this from happening?
Heres my tune also
Why are you adding fuel at "light boost"? Are you really at
positive manifold pressure at cruise? I'd think not. Perhaps
you ought to be pulling out timing rather than pushing
fuel. Especially if you're still in closed loop, pushing fuel
via the VE table is just pushing an error and you're seeing
the natural response.
Originally Posted by jimmyblue
Its not positive at cruise but when it gets around half throttle, when the manifold pressure does exceed vacuum and builds like 5lbs of boost it dont seem to like 14.6 AFR's. I have PE coming in a 2000 now and it took care of the problem but is this the wrong way to go about it???
Last edited by aaron.amrace; 05-08-2012 at 02:25 PM.
Your PE enable TPS is too high. Lower it and raise your PE enable MAP.
I usually run a histogram that plots TPS over the VE table to see what it takes to get to the high load areas.
You're also using a 1 bar OS on a boosted car. If you're not going to upgrade to a custom OS, I'd set Dynamic Airflow High RPM Disable to something like 2000 rpm and tune it using just the MAF.
Yeah i moved my kpa to like 95 and moved tps down to the 40s and that helped it out alot.
What exactly am i doing when i move the Dynamic Airflow High Rpm to like 2000? Never really messed with it. I put the maf back in and was able to get some fuel in those funny light acceleration spots.
By setting it to 2000 you're disabling the use of the VE table after that rpm.
do i leave the WOT max entry disabled? Thanks for all your help
I have a dip in AFR when Dyn Cylinder air G/cyl increases but idk what is commanding that fuel. Rpm, Maf, Tps all basically stayed the same but the g/cyl increased and it dropped the AFR from 12.5 to like 10.8. thanks
Here it the latest log. This truck is driving me crazy
Is the commanded AFR moving, or just the result?
You don't indicate what MAP is doing. Whenever MAP
is unsteady, MAF is ignored and you revert to the
speed density layer. The two may be discrepant at
the region where this happens.
Trucks tended to have kooky low burst knock retard
thresholds (g/cyl/sec, delta dynamic cylinder air mass)
and if you see a lot of excess retard when you open
the throttle, or just on hard steady-throttle acceleration,
this may be bugging. I've seen this dog a '99 truck, and
when raised to F-body type thresholds it turned into a
tire-fryer. This ought to not impact AFR readings though
if you had (say) a persistent misfiring under normal
conditions, that might spoof the O2 sensor toward the
lean side, and spark-pull might give you the true AFR
for the air and fuel being shot. But that would be odd
at an already enriched fueling position, I'd think.
If you look, you're commanding 11.80 and getting anywhere between 9.80 and 11.20. Tuning is what we do to correct this. Make your Actual AFR the same as your Commanded AFR.
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