I was playing around with an LM-2 AFR meter and logger, posting a couple plots and looking for some insight.[attachment=8911:LM2_afr1.pdf][attachment=8912:LM2_afr2.pdf]
I tapped into the wire harness near the ECU to get the TPS signal, I made a jumper between the right side injector for the RPM pick up.
First plot is around 45% throttle the motor is loaded down pretty good, simular to a dyno run, there is some glitches on the TPS, I don't know if that is real or something to do with the LM-2. RPM looks kind of noisy, couldn't say if it is normal, maybe if I get it from the spark it would be more stable.
On this run notice that when I back off the throttle and have some engine braking the AFR goes lean, is this normal? I don't see the afr on dyno charts at the end of the run. If not normal then I think it could be an air leak either through the injector bungs or through the IAC or whatever that air bleed servo is called.
The second plot shows the same glitches in the TPS, TPS around 55%, one thing I notice right off, the AFR starts out a little leaner than I'd like then at around 6300 RPM, 95 second mark, the AFR just drops down from 14 to 12? is this just an area wherethe map changes? Notice when the throttle is chopped the AFR goes lean again, normal?
Air Fuel Ratio
When you let off the throttle you will go lean on most quads. You can actually change the afr for that condition if you are running too lean. The fuel setting can change every 5-10%% rpm if i recall. Its been a little while since i messed with the mapping. So you can potentially have alot of changes in your map. If you can make a few runs and make that repeatable then you can go into the map, make your change and then see how it affected your afr curve.
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cannondale27
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Wow that afr1 is all over the place afr2 is workable.Have you seen any other charts from the LM1?There must be some setting wrong with it.On a normal dyno run you stop the logging the instant rev limit is hit so no it wont show lean spike which is normal and actually designed to help limit engine braking.
From the looks of the afr2 chart there may very well be a issue with your T.P.S. try hooking it up to D&M and seeing if its skipping in that area.Or you just moved your thumb a bit.
Concentrate on full throttle runs first then half and last partial and idle.Use your throttle limit screw to make this error proof.
From the looks of the afr2 chart there may very well be a issue with your T.P.S. try hooking it up to D&M and seeing if its skipping in that area.Or you just moved your thumb a bit.
Concentrate on full throttle runs first then half and last partial and idle.Use your throttle limit screw to make this error proof.
QUOTE (cannondale27 @ Sep 10 2009, 08:44 PM) <{POST_SNAPBACK}>
Wow that afr1 is all over the place afr2 is workable.Have you seen any other charts from the LM1?There must be some setting wrong with it.On a normal dyno run you stop the logging the instant rev limit is hit so no it wont show lean spike which is normal and actually designed to help limit engine braking.
From the looks of the afr2 chart there may very well be a issue with your T.P.S. try hooking it up to D&M and seeing if its skipping in that area.Or you just moved your thumb a bit.
Concentrate on full throttle runs first then half and last partial and idle.Use your throttle limit screw to make this error proof.
From the looks of the afr2 chart there may very well be a issue with your T.P.S. try hooking it up to D&M and seeing if its skipping in that area.Or you just moved your thumb a bit.
Concentrate on full throttle runs first then half and last partial and idle.Use your throttle limit screw to make this error proof.
I run a twist throttle
Funny story about trying to repeat runs, I did this on the street out by my work, I found that if I roll up to about 20mph then apply the rear brakeI can open the throttle and really load the motor like a dyno, works great! I would not suggest doing it unless you have lots of spare brake parts
there's no cooling, warped the rotor and crystalized the pads 
That is all the spare parts I've got, first trip out to Glamis is around October 20th so it's going to have to wait 'till then. I figure I can take it to Olds and run it up one of the steep sides.
I also had a pressure transducer on the fuel pressure recording, I was curious to see if the pressure changed under loaded conditions, the signal was kind of noisy but it appeared to hold steady at around 44 psi.
LM-2 can record RPM plus 4 channels of 0-5 vdc data at about 12 samples/second
QUOTE (Happyboy @ Sep 10 2009, 07:10 PM) <{POST_SNAPBACK}>
When you let off the throttle you will go lean on most quads. You can actually change the afr for that condition if you are running too lean. The fuel setting can change every 5-10%% rpm if i recall. Its been a little while since i messed with the mapping. So you can potentially have alot of changes in your map. If you can make a few runs and make that repeatable then you can go into the map, make your change and then see how it affected your afr curve.
That is good to know about the AFR being normal lean when letting off, I'm going to have tomake quite a few runs at different throttle positions. I'm going to have to try to match up points where things happen and try to adjust in the map.