2008 tahoe 5.3l afm/dod delete issue

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Nickct203

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Small update hoping moving in the right direction. Noticed 1 of the fuses was blown for o2 sensors. Replaced it and replaced the 2 back ones. Driverside bank 2 sensor had bare wires and broken wires. So I figured that could be the cause of the fuse blowing. Also now after changing those 2 sensors starting the truck it runs good for the first 10 to 15 seconds then falls back into the rough idle and p0300 pops again. Also all you smell now is raw fuel.
 

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Small update hoping moving in the right direction. Noticed 1 of the fuses was blown for o2 sensors. Replaced it and replaced the 2 back ones. Driverside bank 2 sensor had bare wires and broken wires. So I figured that could be the cause of the fuse blowing. Also now after changing those 2 sensors starting the truck it runs good for the first 10 to 15 seconds then falls back into the rough idle and p0300 pops again. Also all you smell now is raw fuel.
Careful running it that way. It will kill the cats.
 
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Nickct203

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Careful running it that way. It will kill the cats.
I haven't gotten a chance to go mess with it yet today, have to bring my daughter for her driving test. But my son has a innovate scanner that reads the cylinders in real time so I can see which ones aren't work right.
 

mikez71

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Sounds like it may need a tune.. Something about VE (volumetric efficiency) tables that need to be filled in maybe?
Just a guess, but something I keep seeing mentioned for MAF deletes...


Sorry I don't actually know anything about it..
Worst case you can reinstall the MAF and flash the stock program, not sure how good/bad it will run with your cam..
 

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Ignoring the huge red flag that your buddy had the mechanical prowess to tackle an AFM delete & cam swap but didn't know it needed to be tuned afterwards, I would recommend going back over everything that was touched en route to pulling the cam and heads. Sensors, wires, harnesses, everything.

Once you're warm and fuzzy that nothing is broken or incorrectly installed, consider getting your original ECU tuned for the mods. Being that it is out of the vehicle already, there are a lot of options for mail-in or remote tuning. I'm more than confident Blackbear or another tuner can help you out. Best of luck and I hope you get it sorted out and back on the street.
 
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Ignoring the huge red flag that your buddy had the mechanical prowess to tackle an AFM delete & cam swap but didn't know it needed to be tuned afterwards, I would recommend going back over everything that was touched en route to pulling the cam and heads. Sensors, wires, harnesses, everything.

Once you're warm and fuzzy that nothing is broken or incorrectly installed, consider getting your original ECU tuned for the mods. Being that it is out of the vehicle already, there are a lot of options for mail-in or remote tuning. I'm more than confident Blackbear or another tuner can help you out. Best of luck and I hope you get it sorted out and back on the street.
Thank you, I was actually going to go this route just for the sake of it. This is the entire reason I don't like anyone else touching my vehicles. Cause now I'm stuck with a widely tore open can of worms. Oo just found out also his boss was doing stuff with the scanner also after I had left the garage last Sunday, where the few things I did do and had it running with no codes and idling correct. All that was supposed to get done at that point was button everything up and tighten everything down. But low and behold not what happened. Going to start this afternoon with pulling the plugs to see what they look like again. Will update soon.
 
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Nickct203

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The scanner I borrowed from my son allowed me to disable each injector 1 by 1. Cylinder 1,3 and 2 made little to no difference when disabled. I pulled the plugs in those 3 and 1 and 3 were soaked. 2 wasn't as bad. So gonna swap coils to see if that helps those 3 and messes up the ones they were swapped with.
 
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Ok so I swapped coils, cleaned plugs and still had the same issue with cylinders 1,2,3. Pretty sure my injectors on those cylinders are bad. Plugs were soaked in fuel. And disabling those injectors didn't matter to the engine running. They have power going to them as I can pulse them with the scanner. Any ideas before I continue and buy the new injectors
 

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Ok so I swapped coils, cleaned plugs and still had the same issue with cylinders 1,2,3. Pretty sure my injectors on those cylinders are bad. Plugs were soaked in fuel. And disabling those injectors didn't matter to the engine running. They have power going to them as I can pulse them with the scanner. Any ideas before I continue and buy the new injectors


if you have one handy, you might do a compression check on those cyl before throwing money at it. Just incase

I've used this way to check an injector is working before. it did a good job of opening one up that wasn't spraying much. never tired it on one that is wetting cyl down thou.

depending on where you live, you might find a race shop that has an injector cleaner/tester and have them flowed for less than new injectors.
 

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