Maf fail dificulty for sd tune. School me!!

[autoaddictions]

I have 3 bar SD tune in my LS swapped s10. The engine runs amazing I swapped the rear to a 3.08 and im trying to get the WOT shift points dialed in. it wont shift into 2nd at WOT. Ever time i make a change to try and resolve the no shift problem it wont start, it just cranks and cranks. If i let it sit for a night it will start right up. The scanner dtc tells me the maf is not failing. I have set the 102 103 104 to every combination possible as well as set maf feq to 0hz. I have to make changes every 12 hours so it can sit overnight. Can anyone give me some suggestions here. Im ready to loose my mind. I can post my tune if that helps.

[5FDP]

I just leave all 3 boxes checked and have them fail on first error. With everything else setup right it fails the maf right away and starts fine.

[UKMeskin]

I was just doing this myself. I like to leave the "SES enabled" box checked on all 3 codes (p0101, p0102, p0103) when I'm in SD. I set the boxes to the right of the code to "1 mil on second" then make sure the MAF is set to 0hz.
You should get the "check engine" light. That reassures me that the MAF has an issue and the vcm is reading off the VE table ie. Sd hope this helps.

[autoaddictions]

i will try this.. I have tried tons off combinations. The result is always the same. I don't understand why it will fail the maf and set the code every time if i let it sit for hours. But if i flash then try to start it right back up it wont set the code and therefor the engine wont start.

[UKMeskin]

That's weird. If it does it again maybe disconnect the battery and see if you can get a reboot or something. I would also double check the OBD2 port itself. Make sure the wiring is clean and everything is where it supposed to be?

[Jay@HAP]

What ECM are you using? Some ECM's have a hard time failing the MAF after a reflash.

[hellbents10]

Right on the ones that give me trouble I populate the maf table on the first cell to give it enough inj PW to idle for a few seconds to fail the MAF.

[autoaddictions]

Im using a ecu from a 2002 chevy blazer as well as the dash this way i have a working dash with a tach and speedo ect. the harness was re pinned for the extra 2 injectors. Then segment swap for the 4l80.

What ECM are you using? Some ECM's have a hard time failing the MAF after a reflash.

[autoaddictions]

Hellbents10 Can you post up a tune that u did this too so i can see what settings u used. Id like to try it. I have no maf sensor in the truck is one required for this trick..

[matty b]

I was just doing this myself. I like to leave the "SES enabled" box checked on all 3 codes (p0101, p0102, p0103) when I'm in SD. I set the boxes to the right of the code to "1 mil on second" then make sure the MAF is set to 0hz.
You should get the "check engine" light. That reassures me that the MAF has an issue and the vcm is reading off the VE table ie. Sd hope this helps.

You shouldn't be offering advice up to anyone when you yourself have yet to get through your first tune. Asking questions is fine, DO NOT tell others what to do when you dont know what you are doing. I wouldn't tell someone how to design a toilet even though I've sat on one for most of my life and you shouldn't be giving tuning advice because you've used the editor on one truck and are still asking questions about it.

There is a reason to set MAF to fail on first failure and setting it to fail on second causes issues. Leaving the CEL on is fine, but fail on second error is not.

Sorry to excoriate you, but needs to be said.

[hellbents10]

Just populate the zero hrz table with a number like 2lb/min for instance and see if that is enough fuel to keep it running for a couple of seconds till MAF fail. No MAF needed for this trick.

[MikeOD]

On the gen 3 vehicles that give me trouble failing the MAF (some are worse than others), I've found if I go into Engine - Airflow - Dynamic and set the "MAF Airmass Filt" to 0, this seems to help them start/run before the MAF fails.

Always set the fail high code to MIL on First Error and then set the high frequency fail to 0 hz. There's no need to touch the other MAF codes.

[turbo 6l]

add some fuel on the open loop fresh air table ...i had one do this to me recently had make it 1.20 to the open loop fresh table try that hth

[mbray01]

Mil on first error, not second
also I will say this, that setting hz to "0" has given me an issue on a vehicle before. Something in the coding as being an impossible number, so it wont fail maf. Anyway, I always set maf fail as a number greater than zero. Some say 1hz, I usually set it at 100, that way it sees it sweep, then fails it
never had an issue since!
but thats my .02