lean after startup first 5 minutes
09-12-2012, 03:19 PM
#21
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doesn't change, that's just kooky. Unless you're not in
open loop (at cold start?).
Says to me that this may be a measurement error (air
in exhaust, misfiring, WBO2 accuracy) if the commanded
AFR actually responds to EQ table as it should, but the
indicated AFR does not.
09-12-2012, 03:32 PM
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If you change the commanded fueling and the fueling
doesn't change, that's just kooky. Unless you're not in
open loop (at cold start?).
Says to me that this may be a measurement error (air
in exhaust, misfiring, WBO2 accuracy) if the commanded
AFR actually responds to EQ table as it should, but the
indicated AFR does not.
doesn't change, that's just kooky. Unless you're not in
open loop (at cold start?).
Says to me that this may be a measurement error (air
in exhaust, misfiring, WBO2 accuracy) if the commanded
AFR actually responds to EQ table as it should, but the
indicated AFR does not.
ok ive been playing with it today.... all this is only happening in OPEN LOOP
i changed my OLFA eq ratio to command 13.61 (1.08) in all temps 140 and above in the table and in vcm scanner i turned closed loop off and as soon as i did that AFR shot straight to 15.7
but once i put it back in closed loop it follows the commanded AFR and runs good
but my problem is why would it be backfiring in OPEN LOOP?? it only does it in OPEN LOOP? closed loop its perfect
09-12-2012, 04:36 PM
#23
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I'm confused.
In closed loop you can only get stoich AFR (14.7 gas) and
will pull to that target subject to the O2 sensor accuracy.
Conversely, if your commanded AFR is not the stoich value
then you are not in closed loop at that point. Now in closed
loop, the open loop EQ vs ECT vs MAP will be ignored.
So what I make of this is that 13.6 commanded delivers 15.7
out the pipe (as indicated by the wideband, at least, which
is still subject to spoofing by stuff like misfires). But I would
expect less misfiring at rich, than at stoich.
Can you say what your delivered injector PW was, for closed
loop and for 13.8 commanded? You would expect 8% higher PW,
while 15.7 if real would have to be 8% lower at same RPM*MAP.
If you see that fuel is in fact fatter, but indicated AFR is leaner,
then we're back to some sensor spoofing type problem; if fuel
is lean despite commanded rich, that's a different direction to
chase. Like first, see the commanded AFR PID and whether it
follows your EQ table, or is following something else.
In closed loop you can only get stoich AFR (14.7 gas) and
will pull to that target subject to the O2 sensor accuracy.
Conversely, if your commanded AFR is not the stoich value
then you are not in closed loop at that point. Now in closed
loop, the open loop EQ vs ECT vs MAP will be ignored.
So what I make of this is that 13.6 commanded delivers 15.7
out the pipe (as indicated by the wideband, at least, which
is still subject to spoofing by stuff like misfires). But I would
expect less misfiring at rich, than at stoich.
Can you say what your delivered injector PW was, for closed
loop and for 13.8 commanded? You would expect 8% higher PW,
while 15.7 if real would have to be 8% lower at same RPM*MAP.
If you see that fuel is in fact fatter, but indicated AFR is leaner,
then we're back to some sensor spoofing type problem; if fuel
is lean despite commanded rich, that's a different direction to
chase. Like first, see the commanded AFR PID and whether it
follows your EQ table, or is following something else.
09-12-2012, 04:52 PM
#24
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I'm confused.
In closed loop you can only get stoich AFR (14.7 gas) and
will pull to that target subject to the O2 sensor accuracy.
Conversely, if your commanded AFR is not the stoich value
then you are not in closed loop at that point. Now in closed
loop, the open loop EQ vs ECT vs MAP will be ignored.
So what I make of this is that 13.6 commanded delivers 15.7
out the pipe (as indicated by the wideband, at least, which
is still subject to spoofing by stuff like misfires). But I would
expect less misfiring at rich, than at stoich.
yes that is what its doing....but yet im getting backfiring and hesitation
Can you say what your delivered injector PW was, for closed
loop and for 13.8 commanded? You would expect 8% higher PW,
while 15.7 if real would have to be 8% lower at same RPM*MAP.
If you see that fuel is in fact fatter, but indicated AFR is leaner,
then we're back to some sensor spoofing type problem; if fuel
is lean despite commanded rich, that's a different direction to
chase. Like first, see the commanded AFR PID and whether it
follows your EQ table, or is following something else
i dont know what the injector PW was.......the commanded AFR PID follows the eq table in OL.
In closed loop you can only get stoich AFR (14.7 gas) and
will pull to that target subject to the O2 sensor accuracy.
Conversely, if your commanded AFR is not the stoich value
then you are not in closed loop at that point. Now in closed
loop, the open loop EQ vs ECT vs MAP will be ignored.
So what I make of this is that 13.6 commanded delivers 15.7
out the pipe (as indicated by the wideband, at least, which
is still subject to spoofing by stuff like misfires). But I would
expect less misfiring at rich, than at stoich.
yes that is what its doing....but yet im getting backfiring and hesitation
Can you say what your delivered injector PW was, for closed
loop and for 13.8 commanded? You would expect 8% higher PW,
while 15.7 if real would have to be 8% lower at same RPM*MAP.
If you see that fuel is in fact fatter, but indicated AFR is leaner,
then we're back to some sensor spoofing type problem; if fuel
is lean despite commanded rich, that's a different direction to
chase. Like first, see the commanded AFR PID and whether it
follows your EQ table, or is following something else
i dont know what the injector PW was.......the commanded AFR PID follows the eq table in OL.
09-13-2012, 10:49 PM
#32
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If you're getting backfiring and hesitation, that sounds
like misfires to me, and misfires will jack the indicated
AFR.
Do you see misfires, or have detection disabled?
Is there perhaps some kind of spark advance issue, maybe
in the spark vs EQ if not the main table, that's pushing it
too far (forward or back)?
like misfires to me, and misfires will jack the indicated
AFR.
Do you see misfires, or have detection disabled?
Is there perhaps some kind of spark advance issue, maybe
in the spark vs EQ if not the main table, that's pushing it
too far (forward or back)?
09-14-2012, 11:14 AM
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ok so an update..... i got to thinking about all of this and all this started right after i dialed my MAF in.... so i got up this morning and uploaded my previous maf tune into my car and it still reads lean but the backfiring is still there but not like it was.... hesitation was gone too... does the MAF have anything to do at idle after startup with it being in OL???
jimmy... i show no misfires ...
98camarod... ive read that article before
im glad both of you are giving some ideas... keepem coming
THANKS
jimmy... i show no misfires ...
98camarod... ive read that article before
im glad both of you are giving some ideas... keepem coming
THANKS
