split BLMs while driving - normal?
Thread Starter
Race Director
Joined: Nov 2000
Posts: 17,103
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From: stop the fun suckers
split BLMs while driving - normal?
I have a small split in BLMs while driving.. maybe 10 counts or so MAX.. in some fuel cells then are the same (126-128) and in others the side that was usually leaner goes richer and vice versa.. is this normal operation?
Race Director
Joined: Apr 2000
Posts: 15,344
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From: Texas
Re: split BLMs while driving - normal? (BluByU)
I have a small split in BLMs while driving.. maybe 10 counts or so MAX.. in some fuel cells then are the same (126-128) and in others the side that was usually leaner goes richer and vice versa.. is this normal operation?
Thread Starter
Race Director
Joined: Nov 2000
Posts: 17,103
Likes: 39
From: stop the fun suckers
Re: split BLMs while driving - normal? (96GS#007)
good tip... I'll check it out tonight and post results.. :thumbs:
*edit* This is some info I took yesturday.. This might help with the diagnostic.. maybe not..
I took my laser heat detector to the engine today at work to see how shes doin’ The end exhaust posts of cyl #1, #7 and #8 were about the same at 430-480* at idle.. the center (shared) exhaust ports of #2,#3,#4,#5 were similar at about 510-530*.. the only odd ball was cyl #2 at a measly 400-420*
Next I checked the temps of the valve cover bolts figuring that the heat for the adjacent rocker arms would be transferred by way of induction and or raditation and they all came out in the 180* range.. except #2 was only 150* and #8 was 210*
What does this tell me.. probably not a whole lot.. But I’m going to put the valve cover and check the valve adjustment for #2 as well as inspect the plug and wire.. do you have any thoughts on this reasoning?
[Modified by BluByU, 7:20 AM 1/30/2004]
*edit* This is some info I took yesturday.. This might help with the diagnostic.. maybe not..
I took my laser heat detector to the engine today at work to see how shes doin’ The end exhaust posts of cyl #1, #7 and #8 were about the same at 430-480* at idle.. the center (shared) exhaust ports of #2,#3,#4,#5 were similar at about 510-530*.. the only odd ball was cyl #2 at a measly 400-420*
Next I checked the temps of the valve cover bolts figuring that the heat for the adjacent rocker arms would be transferred by way of induction and or raditation and they all came out in the 180* range.. except #2 was only 150* and #8 was 210*
What does this tell me.. probably not a whole lot.. But I’m going to put the valve cover and check the valve adjustment for #2 as well as inspect the plug and wire.. do you have any thoughts on this reasoning?
[Modified by BluByU, 7:20 AM 1/30/2004]
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
Re: split BLMs while driving - normal? (ANTI VENOM)
96GS, could you explain the lag time that you were talkin about? I found it interesting, I'm not sure I understood it fully though.
In simpler terms, when I look at my AutoTap or OBD-2 log files, each data record has a time stamp. These time stamps show the delta in time between the data points. It's not unusual when recording a WOT run for instance for the two fuel trims to be different during the first and last records of the run and be identical everywhere else...all because of the time lag and transition.
:)
Burning Brakes
Joined: Nov 2001
Posts: 1,241
Likes: 9
From: Houston TX
Re: split BLMs while driving - normal? (BluByU)
i have scientifically proven i change the fuel trims by relocating the O2 sensor at a different "clock" position on my car. 12 o'clock ends up with roughly +10% fuel trims, versus 9 o'clock needing about +3%, no changes in programming or anything else.
just something i was playing with once...
-michael
just something i was playing with once...
-michael
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
Re: split BLMs while driving - normal? (MSR)
i have scientifically proven i change the fuel trims by relocating the O2 sensor at a different "clock" position on my car. 12 o'clock ends up with roughly +10% fuel trims, versus 9 o'clock needing about +3%, no changes in programming or anything else.
just something i was playing with once...
-michael
just something i was playing with once...
-michael
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Burning Brakes
Joined: Nov 2001
Posts: 1,241
Likes: 9
From: Houston TX
Re: split BLMs while driving - normal? (96GS#007)
sorry, i didn't explain well.
i have different bungs welded into the collector. one for the stock sensor, one for use with a wideband. i tried moving the stock sensor into the other bung and found the above to be true.
so when i say "clock," i mean the sensor on top pointing downward versus on the side pointing outward.
-michael
i have different bungs welded into the collector. one for the stock sensor, one for use with a wideband. i tried moving the stock sensor into the other bung and found the above to be true.
so when i say "clock," i mean the sensor on top pointing downward versus on the side pointing outward.
-michael
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
Re: split BLMs while driving - normal? (MSR)
sorry, i didn't explain well.
i have different bungs welded into the collector. one for the stock sensor, one for use with a wideband. i tried moving the stock sensor into the other bung and found the above to be true.
so when i say "clock," i mean the sensor on top pointing downward versus on the side pointing outward.
-michael
i have different bungs welded into the collector. one for the stock sensor, one for use with a wideband. i tried moving the stock sensor into the other bung and found the above to be true.
so when i say "clock," i mean the sensor on top pointing downward versus on the side pointing outward.
-michael
