MAF tuning help early DBW

I am working on a buddies 65 c10 with a refreshed 5.3 with a small cam 4l60e no stall from a 2000 suburban DBW doner for engine trans harness and ecm and sensors with 33lbs flex fuel injectors swapped in. I wasnt able to fail maf because with maf failed it wont run. Is they a way to fail maf so i can adjust ve on these early DBWs? Im having issues straight maf tuning and think its because of ve blending, from 27ish% throttle to 40ish% throttle afr goes all over the place and pops out exhaust, over or under those throttle positions its fine while in same maf frequency cells. Attached log (which is extra long trying to get as much data to look at for issue) and tune (which is still in progress). At about 11:07:13 is where it shows the most. I know its still rich but why would it jump around so much. We have swapped a bunch of parts thinking it was mechanical first except throttle body because couldnt locate one locally. Thanks for any assistance.

mporte1983 you should put the injection timing Boundary back to 6.50 immediately. This is probably a big part of your pops.

Are you running the 2000 truck manifold and return style fuel rail?

Are you using an external fuel pressure regulator?

What psi fuel pressure are you running?

Next the log lacks a lot of data channels. Please use this list and log.

If you would like to use Lambda for tuning in OL.... transform the WB to EQ ratio.

Are you running E-fans? Your enable speed is set to 30MPH and turns it off at 35MPH? At the end of the log that is why you hit 230* at 12mph slowing down. If you do have E-fans the torque adjustment for fans is 0 out?

Do you have AC?

What is the cam specs?

Cheers

stock intake for 2000 suburban with stock fpr return style rails, 46 psi fuel pressure at idle 58 with vacuum line disconnected, i havent messed with injector timing, no ac, clutch fan but he hasnt made the shroud fit yet.

220/228 575/575 112+2 cam

cant open your attachment

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Originally Posted by mporte1983

cant open your attachment

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mporte1983 download the .xml file into a known file location ( like HPTuners> VCM Scanner> Channel Configs folder) and then open VCM Scanner>> Log File>> Close Log File.

*** If you want to save the Channels you are using now then use the Save Channel Config As icon and save to a folder location you choose BEFORE Close Log File***.

Next in the Channels section (folder with the Gear icon) open Channel Config>> navigate to the downloaded .XML and select it.
Now the Channels will be populated with new ones and next time you log you will have those PIDs reporting.
If you go watch a log from before selecting the Channels I provided it will only show the Channels list that you had when the log was made but it will revert back to the last loaded Channels list for future logs.
You must try to keep the Channels list as short as possible in the Gen3 ECM. It does not have the bandwidth to report more than about 25 Channels and it will slow the data stream. You have to know the limitations and log for a specific task.
Example: If you are adjusting fuel tables then you don't really need the idle stuff and if doing WOT tuning you would not include CL fuel trims, things like that ok.

Happy tuning!

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Originally Posted by mporte1983

stock intake for 2000 suburban with stock fpr return style rails, 46 psi fuel pressure at idle 58 with vacuum line disconnected, i havent messed with injector timing, no ac, clutch fan but he hasnt made the shroud fit yet.

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Someone has changed the Boundary to 7.20. You need to put that back to 6.50. When the time comes to adjust injector timing it is done in the Normal table NOT the Boundary.

This is going to change the fueling, so you will need to pick a fuel mode to use. Looks like james duncan 65 c10 maf OL 4 tune file is set up for MAF only. It is as good a place as any to start again. The injector data is not complete and run those Channels I posted to get an idea how things look AFTER the Boundary is corrected. Change that first and get up to op temp then log. A good habit is to key-on and wait a few seconds then crank it. Some important info is gathered at the key-on before and at startup.


MAP characterization is not quite right. MAP Sensor Linear should be 94.43 kPa. Everything matters.

ok thanks i will try that. all that i have messed with is the maf frequency. i was trying to find a way to sd tune this first but couldnt. the other stuff ive tuned i started sd then maf.

Your VE table is experiencing some "smoothness" issues. Honestly, I'd start with a STOCK VE table for the same size engine, then reduce the 400 column by 30% (X.70), then the 800 column by 20% (X.80), then the 1200 column by 10% (X.90). That would be a good starting point for tuning the VE table with that cam. Then, your MAF frequency table is also a bit dodgy. I would start with an all stock table and try tuning from there. Your current tune has the first 2 MAF codes in the DTC list set to NO ERROR reported. That needs to be fixed. With the other problems.. I might just start with a complete STOCK tune for a 2000 with a 5.3L, change your injector data, change the VE table with the percentages I listed above, and start tuning again. Here's a good video that will help you properly set up the tune for speed density tuning. https://www.youtube.com/watch?v=W4Z4bJ3QSfc
That same guy-goat rope garage-also has videos on MAF TUNING and will again give you the proper steps to set up the tune for dialing in the MAF curve. Until you get the tune sorted out, I would highly recommend you STOP driving the vehicle as your current tune could potentially damage the engine. That popping through the exhaust "could" be an engine so lean it is lean misfiring.. That's bad joo-joo. If you have specific tuning questions, post them and I'm sure someone here will assist you as best they can.

What happens when you disable MAF and try tuning SD? If it tries to stall maybe get to op temp under MAF and then load SD. Or use pedal until the SD tune can idle on it's own. The BRA is set ok so if it idles in MAF it should idle in SD?

***What is the intake tubing size with MAF housing?

Try it again with the Boundary corrected and those Channels. If you make a cold start idle log in SD you may need to get it up to op temp before it is stable enough to run by itself.

The only log I have is from a driving log. Need a solid idle log either in MAF or SD and we can go from there.

if i disable maf cold or hot it wont start so makes it hard to sd tune if it wont even run no matter throttle position, i havent touched ve table no point if i cant disable maf, my original question was how to sd a maf only ecm, as far as dodgy maf im still working on it trying to figure out the popping issue between 28% throttle and 40% throttle so i can move past this point, im about to head over there and try what hondaeater suggested and maybe make his fan shroud fit its 105 here today in east texas. i have watch goat rope a few times for info i used his ltft maf tuning to get my long terms in check on my 79 c10 5.3 which i tuned no problem 3 years ago along with a turbo 4.3 that i daily drive 80 miles one way. has spectra cone filter with 4 inch piping about 2 foot long with 90 at tb maf at filter. i will post up an idle log when i get back to my wifi, it idles great.

Make sure to scan for DTCs.
You need to change the DTC for P0101, P01012, P0103 to MIL on first error. It doesn't "fail" the MAF if you have it Noerror reported. That is probably why your SD is not working.

yeah i didnt realize dtcs were like that i usually leave it alone to fail maf and just 1 out the diag for maf, so went through dtc list and turned a bunch back on, he had another buddy do the vat and emission delete stuff so he could run it before i had time to get over there so i assumed it was done right and you know what they say about assuming, so i get over there and he had the timing cover pulled off said it had some oil drips on the ground this morning so he replaced the crank seal and cover gasket so helped put that together and made a fan shroud, went to start it and no fuel pump, he went cheap on a lot of parts and i found the connector inside his sending unit melted, he used a jeep cherokee tank and square s10 sender to get tank out of cab and got them from amazon so maybe the popping is from the pump loosing connection he is ordering a dorman sender and will try again next weekend back to day job tomorrow. was talking to another buddy that tunes and he said he always has issues with that dbw setup with the external tps and recommends p59 style, which i have all the stuff to do the swap but im determined to get this worked out. was also thinking maybe the tb is fluttering in that tps area going to try and found one for testing purposes.

How is the project progressing? Did you go with the p59 TB and get the fuel sorted out?

sorry its been a while since i have updated, my buddy ended up in the hospital with some health issues so truck was put on back burner, we did end up going with the p59 setup and tuned out just fine for me, i did some digging through the harness after we were finished and found a lot of corrosion in the wiring so im sure that was the problems i was having.