I could really use some help. My car is missing badly from about 2000 rpm -2700 rpm with moderate to heavy load. Checkout attached log file. Best attempt was around 8:51:47missfire test.hpl
I could really use some help. My car is missing badly from about 2000 rpm -2700 rpm with moderate to heavy load. Checkout attached log file. Best attempt was around 8:51:47missfire test.hpl
It may be hardware which is where I am leaning but because it is in a very specific range it leads me to believe it is in the tune.......
I noticed your Lambda was 2.0 when the misfiring started, I believe that is super lean.
When it is reading 2.0 lambda it is in DFCO. You will notice i am transitioning into WOT and AFR comes around although it really is not stable. I have tried being on both sides of the STFT + and -. still misses either way. If you watch the misfire count it does not really move until 2300 rpm. The lambda is bouncing around .77-.88. I am commanding .84 but it does not stabilize until 2600. At which point it stops most misfires.........still a few more afterward. Do you typically see the AFR bounce around when transitioning to WOT?Originally Posted by HeavyLineStreetCars
That MAF signal looks dirty...........I've seen worse but still looks ugly
You could try lowering the WOT start point and see if that helps. I see a lot of 3V tunes starting it at 75-150 instead of the factory's 460.
missfire test 2.hpl Attached is another log file. I started earlier, 1700 rpm or so and pulled to 3500-4000. Several pulls. Added a few channels.
missfire test 7.hpl Another log from today. Time for the misfire starts at 7:31:28. I'm at a loss
Looks like to me your MAF signal is everywhere, esp when it starts the misfire. If you look, it's calculating all kinds of fuel ratios, I would imagine because it thinks there's varying amounts of air going in. Maybe fan wash? Or dyno fan blowing at the mass air meter, messing it up?
Also, looks like you're holding it on an eddy brake dyno? If so, what does it do lugging it like that on the road?
I agree, very dirty signal. JLT cold air, filter on so it should keep the air straight.The cold air has been on for 2 years and I only started noticing this over the last 6 months or so. This is on the street. And it is popping and sputtering badly until around 2400 when it starts cleaning up a bit. I can make it happen in any gear with the converter locked. Otherwise it blows right by it and I never notice it. Even part throttle with cruise control on occasionally.......load dependent.
Ok, how do plugs look? Maybe the skipping/sputtering is making the maf go all to hell, esp if backfiring through the intake. Maybe try a new set, see if it helps anything. This is n/a, correct?
It is NA. I installed new plugs and brought the gap down to .040. Compression test, best was 190, worst was 180 but all others were somewhere between. Still makes good power, right at 500 at the wheels.
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