OLSD tuning, Maf fail but had to double VE to get to idle
#1
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From: ft worth texas
I was trying to tune the VE via wideband, followed every damn tutorial I could find on sd tuning. I pulled the maf signal wire and set up the tune the way it should be (I think) to be OLSD. When the truck initially starts it goes to 12ish on the wideband which I assume is from afterstart enrichment. Then truck will stumble after about 3-4 seconds and lean out to 18, 19, 20 afr then die. So for shitz and giggles I loaded my stock VE table before engine swaps/mods and tried, same thing. So I multiplied the table 100% and the startup was stupid rich but then idled around 12's, so I decreased the whole table 15% and the afr was now 13.5ish jumping around.
So my question is... Obviously that's not right to have the VE table increased like that but I'm missing something I guess...
I've even zeroed the maf curve out trying another method I read about, no difference.
Tune attached
EDIT:I attached the tune that I currently run before I tried to tune the VE table
So my question is... Obviously that's not right to have the VE table increased like that but I'm missing something I guess...
I've even zeroed the maf curve out trying another method I read about, no difference.
Tune attached
EDIT:I attached the tune that I currently run before I tried to tune the VE table
Last edited by cdub81; Mar 31, 2014 at 07:23 PM.
#5
Joined: Jan 2006
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From: Huntsville, AL
When you said you pulled the wire I didnt know what you meant. If the MAF is really failed then you should get the MAF DTC.
If it works decently after doubling the VE table I would say your IFR table is wrong.
If it works decently after doubling the VE table I would say your IFR table is wrong.
#6
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From: ft worth texas
Here's the IFR table:
41.73 41.98 42.23 42.47 42.72 42.97 43.22 43.47 43.71 43.96 44.21 44.46
44.71 44.95 45.20 45.45 45.70
Tune is attached also
#7
I dont have HPT but if your MAF is reading properly, and your VE table isnt it sounds more like a calculation with the cylinder volume to me. Like I said I cant even open the file, just something you might want to make sure is correct. Was your MAF also increased at one time? Another thing you might want to check is that if you have a flex fuel vehicle and it is reading an inaccurately high ethanol value it could cause that problem. If you dont use E85 it might be best to just tune it out.
Last edited by Gadgetized; Mar 31, 2014 at 09:34 PM.
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#8
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From: ft worth texas
I dont have HPT but if your MAF is reading properly, and your VE table isnt it sounds more like a calculation with the cylinder volume to me. Like I said I cant even open the file, just something you might want to make sure is correct. Was your MAF also increased at one time? Another thing you might want to check is that if you have a flex fuel vehicle and it is reading an inaccurately high ethanol value it could cause that problem. If you dont use E85 it might be best to just tune it out.
Yes the maf and VE tables have been changed, truck runs good, I was just going to try and work on the VE more to get some throttle transition rich/lean swings calmed down, they're not to bad but maybe I'm OCD.
No flex fuel, I'll just tweak on the maf some more until I can get this figured out.






