mckenzies 2008 gmc.hptAttached is a file of my current tune. Work I have done to the truck includes non DOD cam, non DOD lifters and all associated gaskets and o rings. The problem is even after I have disabled the DOD and did no report on the cylinder codes including unchecking the ses box's it still runs on 4 cylinders. It sounds like for a split second when it first starts it is running on all 8 but almost instantly switches to 4. Any ideas what I am missing?mckenzies 2008 gmc.hpt
Last edited by Nato1; 05-11-2019 at 04:46 PM. Reason: Wrong tune
Are you logging any of the DOD status flags in the scanner to see if it's actually trying to command DOD? Have you checked spark and injector pulse on cyls 1-4-6-7 when it's acting like DOD is active?
No I have not, can you do that thru the editor or scanner?
Did you replace the VLOM with a plain valley cover or just leave it unplugged? Are you absolutely sure the camshaft is the correct part, and not accidentally a stock replacement DOD cam? Misboxed or something? What cam did you use, from where? Was anything marked on the cam itself, with numbers/codes that match the box and non-DOD application?
First step is to add the channels for DOD stuff, and current misfires for every cylinder.
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If it's missing on any cylinder other than 1-4-6-7, the DOD ones, it's not a DOD issue. If it's not missing on ALL the DOD cylinders, it's not a DOD issue.
If the above stuff doesn't turn up anything useful you can do a power balance test through the scanner. Or unplug injectors one at a time. And then check spark with a spark tester.
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One thing I want you to do first: Read the current tune from the truck, save it as a new file, don't make any changes at all, and attach it here. I want to see what's actually in the ECM right now, not the file you've been using.
I did replace the VLOM with a non DOD and I did run it with the plug unplugged and also I have tried to plug in the old senor off of the DOD valley cover to no avail. here is the latest tune on the trucknewest tune 2008 gmc.hpt
Also I bought the parts from a company called AMS Racing. I did the swap a few weeks ago and just burnt the box this morning and did not get the number off of the cam. The fellow I talked to at AMS assured me that it was the correct cam. for what its worth I suppose.
Yeah, see, the tune you were writing shows DOD disabled, but the one read out of the truck shows it's not. The DOD DTC changes also didn't stick.
Yes I was just looking at that, I should try and remove the dod and the dtcs and write it to the truck and try it again huh?
Yes. Make the changes to the newly-read file, flash, then do another read and compare the read file to the written file.
WOW, Ive been f-ing with this thing for some time now and finally blindsquirrel you have help me eliminate this problem. I think the main issue was I switched computers after the initial tune and it keep wanting me to relicense it. I finally did with the help of you and now she runs on all 8 again. Thank you so much and have a great night!
Not to heckle but why didn't you do this last week when I told you in this thread?
https://forum.hptuners.com/showthrea...a-search/page2
I would figured you would have atleast made the changes and flashed the file again to complete the changes, but I guess not.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
I still don't understand how/why even with the stock tune DOD was being requested (spark & injectors shut off) at idle (or, apparently, all the time). I would have figured that with the VLOM no longer present it would have defaulted to 'DOD inhibited no matter what'.
Ultimately I am to new to this tuning deal and needed a bit of coaching, I appreciate all the help you gave me however when you stopped replying I was honestly at a loss. I had zero experience and didn't realize how close I actually was however by simply have me re read the vehicle. Anyways it worked and I thank you all for the assistance.
I have to ask because I'm in the same boat..Were you able to correct the issue? Ive done everything these guys are saying to just run on 8 cylinders so I can get a good scan but nothing is working.. lol
Read the file from the truck and post it in your own, new thread describing your issue.
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