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Cant figure it out...

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Old Feb 6, 2014 | 11:02 AM
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Default Cant figure it out...

I am tuning my ls1 with hptuners. I have an ls6 intake, torquer v2 cam, prc225 heads, and a circle d 3600 stall on a 4l80. when going wot my maf readings look spikey and im not sure if this is normal or not. Could it be that my maf is bad or my calibration? It is an slp maf with the resistor removed so I guess its basically a Delphi 85mm maf. please help!!
Attached Thumbnails Cant figure it out...-scan.jpg  
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newmufflers1.hpl (629.7 KB, 49 views)
File Type: hpt
newtimingtable.hpt (465.2 KB, 68 views)
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Old Feb 6, 2014 | 12:48 PM
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MAF output should be smooth and at higher RPM the
output should not be able to track any manifold
pulsation / reversion.

Shop manuals say that EMI in the harness can bother
the output quality and they suggest debundling the
MAF wires from the rest, just to see, if output is
flakey - especially if only under certain conditions.

You can get an idea of whether reversion pulses are
bugging it, by swapping on a screened one. If yours
is descreened. But at high RPM I don't think it can
distinquish or follow that kind of action.

I don't see this kind of noisiness on mine, which is
descreened and in standard position.
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Old Feb 6, 2014 | 02:51 PM
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Thanks for replying jimmy. i posted this question on hptuners about a week ago and still havent got a response so i appreciate your time. I will seperate the maf harness from the rest of the harness and scan again. The maf I have is currently screened and is setup in the k&n fipk II kit. I believe it is the same location as stock. So something is wrong the? This isn't something normal if yours isn't acting this way also
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Old Feb 20, 2014 | 09:40 AM
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I have debunked it from the rest of the harness and tried again. Still does the same thing. Any other thoughts?
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Old Feb 20, 2014 | 09:45 AM
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Do you see any corresponding "ripple" on MAP or RPM?
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Old Feb 20, 2014 | 10:13 AM
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Debundled *
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Old Feb 20, 2014 | 10:15 AM
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No I dont. it does not seem to affect the afr rpm or anything. Just the frequency which in turn affects the calc cylair. You can see in the picture where my wideband trails the commanded afr pretty accurately
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Old Feb 20, 2014 | 12:17 PM
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I was advised to just run sd. But I have not converted yet cuz while I am in ve, for some reason when my engine is cold it will not run for crap. If I give it any throttle at all it will just bog and not even move. It does this for a few minutes then it'll start running good. If I can't figure what's going on with the maf then I will switch to sd and try to work that problem out
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Old Feb 20, 2014 | 12:52 PM
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Reduce your bytes to 24 for more frames/sec. Your logging 36. Seen many mafs that were is bit spikey, didn't seem to affect the tune.

Russ kemp
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Old Feb 20, 2014 | 01:32 PM
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hey russ,
here is another scan where I used 20 bytes. so do you suggest I just leave it as is or just jump to sd?
thanks
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Old Feb 20, 2014 | 02:29 PM
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Looks perfectly normal to me. But I always tune the gen III cars in SD that anything larger than a very mild camshaft.

Russ Kemp
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Old Feb 20, 2014 | 04:35 PM
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Any particular reasons why you go sd with the gen IIIs?
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Old Feb 20, 2014 | 04:44 PM
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On anything larger than a very mild cam, after getting the WOT AFR tuned from idle to redline, the part throttle AFR is too rich. Tune the part throttle AFR, then at WOT the AFR is too lean. I've experienced this on several LS1 Camaros & C5 Corvettes.

I fought with my first cam (234/228 113 lsa) back in 2003 trying to get the part throttle & WOT AFR right. Plus there was a long delay for the AFR to respond on a WOT stab in Maf mode. Went SD and never looked back.

Russ Kemp

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Old Feb 20, 2014 | 07:36 PM
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I know this might be a stupid question but when going sd do I do the same as when I'm tuning the ve? Does my low octane have to be the same as my high octane and is my engine light going to be on? Or do I just get rid of the maf and disable the codes associated with it and leave the low and high octane alone?
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Old Feb 24, 2014 | 08:55 AM
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Ttt......
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Old Feb 24, 2014 | 10:24 AM
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Originally Posted by pimpin78transams
I know this might be a stupid question but when going sd do I do the same as when I'm tuning the ve? Does my low octane have to be the same as my high octane and is my engine light going to be on? Or do I just get rid of the maf and disable the codes associated with it and leave the low and high octane alone?
It depends if go SD and use a custom OS or just go SD. If you just go SD then youll need to copy your high timing to your low table. You'll have a MAF code since you cant delete all the maf codes but you can turn off the CEL for P0101,P0102, and P0103 so you light isnt on.
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Old Feb 24, 2014 | 11:29 PM
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thanks LSX. I appreciate all the help and advice you've been giving me. I just went 1 bar custom os so lets see how it works out in sd.
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