2009 Silverado AFM Delete

First time posting here and first time using HP tuners. I appreciate any help that is offered.

Truck comes in from a shop that had done an AFM delete - lifters, plate & new camshaft. The vehicle is a 2009 Silverado, that started life as LMG, 5.3L, VIN 0, with 164k on the odometer. The shop does the mechanical stuff and he has a buddy that has HP Tuners who attempted a tune. Vehicle has a misfire at an idle with the MIL on and flashing. DTC's stored were - P0172 Fuel Trim Bank 2 Rich, P0573 Brake Switch, and P1175 Fuel Trim Cylinder Balance Bank 2.

No P0300 stored, that's odd. Another oddity was BARO was at 82 kPa which puts the altitude at 5 - 7k feet. I'm at roughly 1,500'. Misfire counts are stored on 1, 4, 6, and 7. Cylinder 6 had the majority of the misfire counts. His situation is he needs a California smog test, for which the MIL has to be off with no DTC's stored and the Readiness Flags have to complete testing to pass. It's not going to happen the way it is now.

Relative compression testing was even and a compression test on cylinder 6 (165 PSI) with a leak down test revealed no problems at least on that cylinder.

I decided to put the factory tune in and used HP tuners to disable the AFM/DOD to "Disabled." First go around didn't take. DTC's P3401 - P3449 are set and starting it up it is misfiring on multiple cylinders. It now is setting a P0300 and BARO is at 96 kPa. I did this again after looking at a post that suggested to change DOD to off in all gear positions. I changed the 0's to 1's for all gears. It's a 6L80E, MYC transmission, if that matters.

This time no DTC's set until the engine warmed up and it was idling after a test drive. Cylinders 1, 4, 6, and 7 are counting up misfires that goes away above 1,000 RPM, and it sets a P0300.

Can someone look over the file and make suggestions on what needs to be changed to correct this? Sorry for the length of this post and I appreciate the help!

Thank you!

Attachment 108905

What camshaft did they install?

Post a log if you can, as well as camshaft info

I placed a call to the owner and also the shop to find this out. I have yet to hear from either one. I'll post an update once I have this.

Quote:

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Originally Posted by davidchristian83

Post a log if you can, as well as camshaft info

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Forgive my ignorance, what log are you talking about? I looked at some of the sticky posts and didn't see that and I see the signature of 5FDP - If you don't post your tune and logs...

Thank you!

Quote:

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Originally Posted by scgms1

Forgive my ignorance, what log are you talking about? I looked at some of the sticky posts and didn't see that and I see the signature of 5FDP - If you don't post your tune and logs...

Thank you!

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In the software you downloaded you have 2 separate programs. One is the editor that changes the software and where the "Tune" or *.hpt comes from. Someone can look at that and manipulate or determine if you made mistakes that cause driveability/power issues. The other is the Scanner. This program is the one that takes a recording of your drive and allows someone to view what your vehicle thinks it should be doing and what it is actually doing while it is running. This is the "Log" or *.hpl file. Posting both gives the guys that are good with the entire program a way of really getting to the bottom of a problem and how to fix it.

Quote:

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Originally Posted by TheMechanic

In the software you downloaded you have 2 separate programs. One is the editor that changes the software and where the "Tune" or *.hpt comes from. Someone can look at that and manipulate or determine if you made mistakes that cause driveability/power issues. The other is the Scanner. This program is the one that takes a recording of your drive and allows someone to view what your vehicle thinks it should be doing and what it is actually doing while it is running. This is the "Log" or *.hpl file. Posting both gives the guys that are good with the entire program a way of really getting to the bottom of a problem and how to fix it.

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OK, Got it. Here's that file. I'll put something else up later. If they allowed MP4's here I had some videos, using SnagIt, of Tech2Win which shows more, but...

Thank you,

Attachment 108921Attachment 108922

Attachment 108927

If this scan is correct, you are VERY lean in the idle range (or tip in off idle.... 1200-1600rpm, and 25-27.5kpa)

Also, your o2's, MAF, Spark Advance, and several other things are not set up to scan correctly (look at the pic below of the spark advance, it is supposed to be populated in a grid format. It is only populating in a single row)

Attachment 108928

Send me an email to [email protected] and I will reply with a scanner layout that you can use that will help you a lot. It's specifically for Gen 4 platforms, and already laid out correctly for most data points you will need

Attachment 108931

I have attached a revision of your tune file. The changes are...

- Set in MAF only mode (you need to tune your fueling part throttle MAF first, then VVE, then set it back to Dynamic mode)

- DFCO OFF (you have to disable this while tuning fuel, or it will be incorrect when off throttle)

- Desoot Mode OFF (Same as DFCO)

I would upload this revision, and start working on the part throttle fueling via the MAF vs LTFT for the MAF side, and then once it is lined out part throttle up to around 4000 rpm, you can fail the MAF and switch it into speed density mode and tune the VVE with a wideband.

Before any of that..... Lets get a proper scan on it so we can see more data though.

Here's a link to a buddies site. This is interactive, so you can click on which PID's you'd like to see. The first file is Engine Data 1 and the second is the Misfire Data Screen. This is taken with a Tech2/Tech2Win.

https://www.scanshare.io/share/_HYcf...11,13,17,19,41

https://www.scanshare.io/share/6kqNM...,1,2,3,4,5,6,7

Quote:

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Originally Posted by davidchristian83

Attachment 108931

I have attached a revision of your tune file. The changes are...

- Set in MAF only mode (you need to tune your fueling part throttle MAF first, then VVE, then set it back to Dynamic mode)

- DFCO OFF (you have to disable this while tuning fuel, or it will be incorrect when off throttle)

- Desoot Mode OFF (Same as DFCO)

I would upload this revision, and start working on the part throttle fueling via the MAF vs LTFT for the MAF side, and then once it is lined out part throttle up to around 4000 rpm, you can fail the MAF and switch it into speed density mode and tune the VVE with a wideband.

Before any of that..... Lets get a proper scan on it so we can see more data though.

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Hi David,

I sent you an email. I appreciate the help.

Evidently there's more going on here. I thought, and I guess I'm incorrect, that if I took the factory calibration files, because there were some errors made with the first tune - if I started from scratch and just disabled DOD and turned off the MIL for the VLOM solenoids, that would be all that was needed.

When I first started with this I thought there were 2 things going on - a valve sealing issue and a bad tune. I have a Pico scope over here and did compression and vacuum testing with a vacuum transducer and pressure transducer. I didn't see a problem. I looked at injector pulse width on cylinders 2 and 6 and didn't see any change, so I'm scratching my head on why the misfires are happening on the AFM cylinders.

According to the guy that owns this truck the truck ran fine until a lifter stuck and he decided to do what I described in the first post. This is when I decided to go after the tune. Maybe I'm looking at this the wrong way, but if we take a AFM engine and turn it into a non-AFM engine mechanically and with the tune - it should run fine...Unless there's something mechanically wrong with this. Or there's something else in the files that needs to be changed to account for VLOM solenoids that aren't turning on the MIL, but the factory files are doing something to account for the missing VLOM solenoids. I find it odd that I haven't seen what's causing the misfire on those cylinders. This isn't a "ghost misfire" it runs like crap at an idle.

BTW I left messages for the guy that did the engine and the customer and I haven't heard back from either one. So as far as the camshaft I have no idea what was put in, but the question is why are cylinders 1, 4, 6, and 7 the cylinders that have misfire counts? I could see a camshaft causing misfires, but it wouldn't be limited to just those cylinders.

Thanks again for the help and I'll do what you suggested for set up in the email.

Quote:

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Originally Posted by davidchristian83

Attachment 108927

If this scan is correct, you are VERY lean in the idle range (or tip in off idle.... 1200-1600rpm, and 25-27.5kpa)

Also, your o2's, MAF, Spark Advance, and several other things are not set up to scan correctly (look at the pic below of the spark advance, it is supposed to be populated in a grid format. It is only populating in a single row)

Attachment 108928

Send me an email to [email protected] and I will reply with a scanner layout that you can use that will help you a lot. It's specifically for Gen 4 platforms, and already laid out correctly for most data points you will need

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I believe the lean readings are due to what is causing the misfires in the engine. Loss of ignition causes elevated STFT & LTFT - positive numbers (ECM adds fuel to correct for a 'lean condition') , loss of fuel causes the same effect except higher numbers than ignition. Mechanical problems same thing. So what ever is causing this to misfire at an idle and slightly off idle, I believe would account for running lean. Right?

Which takes me back to - I think a lot of people have attempted this DOD delete and it sounded fairly simple. I couldn't imagine people doing this and living with a truck that runs well under acceleration and a cruise, but runs like crap at an idle.

I?ve seen this happen before, and to the best of my memory it was when someone tried to put standard lifters in with the DOD camshaft, and it had an idle misfire on all DOD cylinders. I didn?t do the engine labor, so I?m just basing on what I was told by the mechanic.

You are correct. If it?s done properly, it will idle and drive just fine.

Correct also about the lean condition could be caused by the misfire. We?ll know a lot more with a little bit more data.

David you are right about the DoD camshaft. You can't put non AFM lifters on those lobes, it will always misfire.

5FDP good info, thank you. I've only ran into this a few times, and I didn't do the mechanical portion on any of them so I shy away from relying on the word of somebody who didn't install cam/valvetrain parts correctly lol. The common denominator between them was..... I ask "Did you replace the camshaft with a delete cam?". I get a weird/blank look, followed by "I replaced all the lifters"..... "That's not what I asked...."..... "I didn't know I had to replace the cam"

Lol, yes... Yes you do. Go do that.

Well, I still haven't heard back from the owner of the truck...And I placed a few phone calls to the guy that did the engine and he never bothered to get back to me.

I finally reached out to him today on Instagram and we texted back and forth. Can you pull up this truck on your computer and let me know what parts were put in here? I don't use a computer. Um, OK.

The long and the short of it. This guy supposedly builds race engines. The guy that owns this truck is his friend and he did this 2 years ago for free, the labor portion. He said the parts used were OEM GM parts for a non-DOD/AFM engine. He couldn't tell me exactly what engine...Sigh Maybe, if the owner ever calls me back he'll have the receipts. One thing I can say about the guy working on this was it was a pretty clean job, which is saying a lot today. I do this stuff for a living, and there weren't too many things I could say were wrong, other than the something big, as I have a feeling this is going to have to come apart again to get the right parts in it.

If it gets this far, any recommendations on which cam to use for this project? Engine RPO? This one is a LMG.

Thanks again!