AFR Issue
11-08-2004, 08:20 PM
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AFR Issue Hi Folks
First, I have turned off the COT but at 5500 my AFR goes from 12.5 to 11.8. it drops off at the top. What is causing this??
Thanks
Bill
First, I have turned off the COT but at 5500 my AFR goes from 12.5 to 11.8. it drops off at the top. What is causing this??
Thanks
Bill
11-09-2004, 06:44 PM
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Hi Folks
I wish somebody has some ideas. Also my PE is;
4400 1.136
4800 1.049
5200 1.036
5600 1.007
6000 1.051
6400 1.046
as you can see it isn't the PE or the COT.
Bill
I wish somebody has some ideas. Also my PE is;
4400 1.136
4800 1.049
5200 1.036
5600 1.007
6000 1.051
6400 1.046
as you can see it isn't the PE or the COT.
Bill
11-09-2004, 07:56 PM
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There is something pretty bent in the system, if
those PE values are giving you anything like 12.5:1
(let alone 11.8:1). Order of 12% error.
Have you modified MAF or IFR tables previously?
those PE values are giving you anything like 12.5:1
(let alone 11.8:1). Order of 12% error.
Have you modified MAF or IFR tables previously?
11-10-2004, 09:30 AM
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Originally Posted by jimmyblue
There is something pretty bent in the system, if
those PE values are giving you anything like 12.5:1
(let alone 11.8:1). Order of 12% error.
Have you modified MAF or IFR tables previously?
those PE values are giving you anything like 12.5:1
(let alone 11.8:1). Order of 12% error.
Have you modified MAF or IFR tables previously?
I have NOT modified the MAF (stock MAF & Table) but have modified the IFR for the new injector. - At WOT, my LTFTs are "0" but in all the other cells it is -4 to -3. I think they are working OK. I did push the timing to 26 degrees at WOT. I agree with you - something is happening after 5500 RPMs. It (AFR)fall like a rock.
Thanks
Bill
11-10-2004, 09:38 AM
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It's going like the -opposite- of fuel starvation which
is really peculiar. The PE table does have that "divot"
at 5600 and you might want to just set the whole
table to a flat 1.150 and do a wideband pull (maybe
rerun the auto-calibration cycle on the WB first) to
see what that produces. Also make sure the Open
Loop Fuel/Air vs ECT vs MAP table is slightly lower
values, at and about your WOT MAP range, so that
the PE table "has the upper hand".
is really peculiar. The PE table does have that "divot"
at 5600 and you might want to just set the whole
table to a flat 1.150 and do a wideband pull (maybe
rerun the auto-calibration cycle on the WB first) to
see what that produces. Also make sure the Open
Loop Fuel/Air vs ECT vs MAP table is slightly lower
values, at and about your WOT MAP range, so that
the PE table "has the upper hand".
11-10-2004, 09:52 AM
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Originally Posted by Bill's 02 Z-28 SS
Hi Folks
First, I have turned off the COT but at 5500 my AFR goes from 12.5 to 11.8. it drops off at the top. What is causing this??
Thanks
Bill
First, I have turned off the COT but at 5500 my AFR goes from 12.5 to 11.8. it drops off at the top. What is causing this??
Thanks
Bill
What is your PE mode delay RPM set to?
11-10-2004, 11:30 AM
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Originally Posted by RedVHO
What is your PE mode delay RPM set to?
I am at work but will check tonight. I don't remember changing that parameter so I think it would be the factory number.
Bill
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11-10-2004, 06:42 PM
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Originally Posted by RedVHO
What is your PE mode delay RPM set to?
I guess when I looked at the PE mode delay RPM, it is set to 5500 - wild. What does that mean and what should it be set to??
thanks
Bill
11-10-2004, 07:18 PM
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Set it to the lowest RPM, where you want PE
"now, dammit!". Also the enrichment rate, you
might as well set to 1 if it isn't (I set mine to 2
just for luck; you just don't want it taking
forever to turn on).
But, why the actual AFR is so far lower than
commanded is still the mystery.
"now, dammit!". Also the enrichment rate, you
might as well set to 1 if it isn't (I set mine to 2
just for luck; you just don't want it taking
forever to turn on).
But, why the actual AFR is so far lower than
commanded is still the mystery.
11-10-2004, 11:55 PM
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Originally Posted by jimmyblue
Set it to the lowest RPM, where you want PE
"now, dammit!". Also the enrichment rate, you
might as well set to 1 if it isn't (I set mine to 2
just for luck; you just don't want it taking
forever to turn on).
But, why the actual AFR is so far lower than
commanded is still the mystery.
"now, dammit!". Also the enrichment rate, you
might as well set to 1 if it isn't (I set mine to 2
just for luck; you just don't want it taking
forever to turn on).
But, why the actual AFR is so far lower than
commanded is still the mystery.
11-14-2004, 05:36 PM
#11
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Originally Posted by jimmyblue
Set it to the lowest RPM, where you want PE
"now, dammit!". Also the enrichment rate, you
might as well set to 1 if it isn't (I set mine to 2
just for luck; you just don't want it taking
forever to turn on).
But, why the actual AFR is so far lower than
commanded is still the mystery.
"now, dammit!". Also the enrichment rate, you
might as well set to 1 if it isn't (I set mine to 2
just for luck; you just don't want it taking
forever to turn on).
But, why the actual AFR is so far lower than
commanded is still the mystery.
I set my "Mode Delay RPM" to 2500 and my enrichment was set to "1" (factory). This is the only change I made and now my AFR at the top end is 12.8 +/-.1. Now I need to add to the PE at 5000RPM and above - Want 12.6. But this is my question, what did I do when I changed the MDR to 2500? It worked or appeared to work anyway but I don't understand why. Also should my MDR (2500) be lower or is that good enough?
Thanks
Bill
11-16-2004, 10:44 AM
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The Mode Delay RPM means that, below this RPM the
power enrichment will be delayed and rolled on according
to the enrichment rate (I don't know the basis units of
this, just more=faster to hit the PE table value).
So you may have been seeing the OLFA table enrichment
at first and then the PE superseding it as it rolled on, or
something like that.
I believe if you have the mode delay RPM below your
converter stall speed (or, your minimum driving style
RPM-in-gear for the M6 guys) it will be well enough
out of the way.
I expect that having too much PE, too low in RPM,
might cost power but this is what you have the PE
vs RPM table for; I have no idea why you would want
anything other than instant gratification.
If you've got a straight PE vs RPM profile and the
delay stuff is gone, then you should be able to see
pretty clearly (by AFR actuals) how much you want
to raise PE w/ RPM.
However if you're picking up the wideband info from
a fast moving pull (like lower gears) I'd check that
the wideband isn't applying too much filtering /
averaging, which might make the output lag by a
bit. On my LM-1 there are settings for that, you'd
like the report interval & time constant to be quick
relative to the rate of engine RPM change (though
this may increase the "noise" and force you to do
some eyeball interpolation).
power enrichment will be delayed and rolled on according
to the enrichment rate (I don't know the basis units of
this, just more=faster to hit the PE table value).
So you may have been seeing the OLFA table enrichment
at first and then the PE superseding it as it rolled on, or
something like that.
I believe if you have the mode delay RPM below your
converter stall speed (or, your minimum driving style
RPM-in-gear for the M6 guys) it will be well enough
out of the way.
I expect that having too much PE, too low in RPM,
might cost power but this is what you have the PE
vs RPM table for; I have no idea why you would want
anything other than instant gratification.
If you've got a straight PE vs RPM profile and the
delay stuff is gone, then you should be able to see
pretty clearly (by AFR actuals) how much you want
to raise PE w/ RPM.
However if you're picking up the wideband info from
a fast moving pull (like lower gears) I'd check that
the wideband isn't applying too much filtering /
averaging, which might make the output lag by a
bit. On my LM-1 there are settings for that, you'd
like the report interval & time constant to be quick
relative to the rate of engine RPM change (though
this may increase the "noise" and force you to do
some eyeball interpolation).
11-16-2004, 11:35 AM
#14
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Originally Posted by jimmyblue
The Mode Delay RPM means that, below this RPM the
power enrichment will be delayed and rolled on according
to the enrichment rate (I don't know the basis units of
this, just more=faster to hit the PE table value).
So you may have been seeing the OLFA table enrichment
at first and then the PE superseding it as it rolled on, or
something like that.
I believe if you have the mode delay RPM below your
converter stall speed (or, your minimum driving style
RPM-in-gear for the M6 guys) it will be well enough
out of the way.
I expect that having too much PE, too low in RPM,
might cost power but this is what you have the PE
vs RPM table for; I have no idea why you would want
anything other than instant gratification.
If you've got a straight PE vs RPM profile and the
delay stuff is gone, then you should be able to see
pretty clearly (by AFR actuals) how much you want
to raise PE w/ RPM.
However if you're picking up the wideband info from
a fast moving pull (like lower gears) I'd check that
the wideband isn't applying too much filtering /
averaging, which might make the output lag by a
bit. On my LM-1 there are settings for that, you'd
like the report interval & time constant to be quick
relative to the rate of engine RPM change (though
this may increase the "noise" and force you to do
some eyeball interpolation).
power enrichment will be delayed and rolled on according
to the enrichment rate (I don't know the basis units of
this, just more=faster to hit the PE table value).
So you may have been seeing the OLFA table enrichment
at first and then the PE superseding it as it rolled on, or
something like that.
I believe if you have the mode delay RPM below your
converter stall speed (or, your minimum driving style
RPM-in-gear for the M6 guys) it will be well enough
out of the way.
I expect that having too much PE, too low in RPM,
might cost power but this is what you have the PE
vs RPM table for; I have no idea why you would want
anything other than instant gratification.
If you've got a straight PE vs RPM profile and the
delay stuff is gone, then you should be able to see
pretty clearly (by AFR actuals) how much you want
to raise PE w/ RPM.
However if you're picking up the wideband info from
a fast moving pull (like lower gears) I'd check that
the wideband isn't applying too much filtering /
averaging, which might make the output lag by a
bit. On my LM-1 there are settings for that, you'd
like the report interval & time constant to be quick
relative to the rate of engine RPM change (though
this may increase the "noise" and force you to do
some eyeball interpolation).
Thanks - It appears everybody can count on you - Great help.
Bill