My timing is doing its own thing....
11-30-2003, 11:17 PM
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My timing is doing its own thing.... Stupid timing...I dont know what the deal is. I ran 11.9@ 113 (this low MPH stuff sucks) this weekend, right off the trailer, on stock tuning. After back to back 11.9's, I was 12.1's and 12.0's. So I decide to hook up Autotap to see whats goin on. On the run I logged, I got between 15.5*-20* of timing...ok, I must have been in the low octane table right...hmm...What makes me be there? I had no knock on the run??? How do I get out of the LOT? Everytime I start the car does it put me in HOT until somethin happens to send it to LOT?
So on the way home, I autotap it some more. This time, its about 22*-23*. Now I dont know whats its reading from. After figuring the MAF G/cylinder, and tracing out the RPMs, the LOT should have had me at 19*, or the HOT should have had me at about 28*?? So why am I in the middle? I dont expect it to be exact but its like its not reading whats in the tables right, and I have yet to mess with them...
I checked the ECT on both A-tap runs, and it fell where there shouldn't be anything taken out..any other ideas? How high should the IAT get before pulling timing?
I am supposed to get to tune on a dyno this weekend, so I would like to have some idea of what this thing is doing...
Also, what do I change in the tranny settings to keep it from downshifting on the dyno...??? Thanks guys...
So on the way home, I autotap it some more. This time, its about 22*-23*. Now I dont know whats its reading from. After figuring the MAF G/cylinder, and tracing out the RPMs, the LOT should have had me at 19*, or the HOT should have had me at about 28*?? So why am I in the middle? I dont expect it to be exact but its like its not reading whats in the tables right, and I have yet to mess with them...
I checked the ECT on both A-tap runs, and it fell where there shouldn't be anything taken out..any other ideas? How high should the IAT get before pulling timing?
I am supposed to get to tune on a dyno this weekend, so I would like to have some idea of what this thing is doing...
Also, what do I change in the tranny settings to keep it from downshifting on the dyno...??? Thanks guys...
12-01-2003, 12:21 AM
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no, TQM has been taken out. The only knock was at the very end of the run, less than 1*
I didnt log MAP values, so I cant exactly check that right now. I am going to log again in the morning on the way to work.
What table is responsible for how much timing is pulled for KR? I see a "spark retard limit" table? Is that it. It goes to a max of -10?
What about how much KR the PCM can see before it starts pulling timing? Is that the "noise level" table? stock mine says 1.7, so does that mean anything 1.7* or higher, then it starts pulling timing?
I didnt log MAP values, so I cant exactly check that right now. I am going to log again in the morning on the way to work.
What table is responsible for how much timing is pulled for KR? I see a "spark retard limit" table? Is that it. It goes to a max of -10?
What about how much KR the PCM can see before it starts pulling timing? Is that the "noise level" table? stock mine says 1.7, so does that mean anything 1.7* or higher, then it starts pulling timing?
12-01-2003, 12:34 AM
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From looking at some other previous logs, it looks as though my MAP KPA for WOT is in the 90's, that combined with a 50* C IAT should be reducing the timing by up to 3*. That would explain the track part, kinda. Not the driving home part though. Would it be bad to get rid of those values...?
12-01-2003, 12:46 AM
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stored value huh? Where are they stored? Or is it something that the PCM comes up with as the car is running? Something thats always being calculated.
If i copied the HOT to the LOT, shouldn't I always see the values that I entered then?
If i copied the HOT to the LOT, shouldn't I always see the values that I entered then?
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12-01-2003, 05:50 PM
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On the EFILive 'board there is some discussion of this,
basically there seems to be some interpolation between
the high & low tables based on some rolling knock count
or something like that.
High MAP (low vacuum) and high load (MAF) will fight
against spark advance. This is probably a prime source
of variation in what timing you get.
My timing runs up to 29 degrees at 6KRPM but is pretty
low in the midband (low 20s at 3KRPM) at WOT. I am
just on the good side of KR (tweaked until it went away).
If you have the logs you might try a scatter plot of spark
vs RPM and look at the bottom side of the "cloud". This
is a pretty linear slope on my car. So anyway, advance
depends on where you read it RPM-wise as well. Makes
some sense to me, since with a fixed burn time that the
advance is trying to compensate, you need more degrees
at higher RPM to get that same fixed-time spark lead.
basically there seems to be some interpolation between
the high & low tables based on some rolling knock count
or something like that.
High MAP (low vacuum) and high load (MAF) will fight
against spark advance. This is probably a prime source
of variation in what timing you get.
My timing runs up to 29 degrees at 6KRPM but is pretty
low in the midband (low 20s at 3KRPM) at WOT. I am
just on the good side of KR (tweaked until it went away).
If you have the logs you might try a scatter plot of spark
vs RPM and look at the bottom side of the "cloud". This
is a pretty linear slope on my car. So anyway, advance
depends on where you read it RPM-wise as well. Makes
some sense to me, since with a fixed burn time that the
advance is trying to compensate, you need more degrees
at higher RPM to get that same fixed-time spark lead.
12-02-2003, 10:18 AM
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Interesting Jimmy...got a link to the EFI Live board?
How should I go about checkin MAP vs MAF? Is there a seperate table for this type of timing?
How should I go about checkin MAP vs MAF? Is there a seperate table for this type of timing?
