So I got something going on and I don't know what, I need some input as to how to trouble shoot.

2011 silverado 5.3, I can't tell you exactly when this started but definitely after my BB Autocal tune. I ran the 91 octane tune for quite a while and I don't remember having problems but I went back to stock tune for my GM certified maintenance oil change (cause it was free) and then loaded back up the 87-89 tune that he sent me, he sent me both the 87/89 and the 91 tunes at the same time. First time I started it, it started then died. I think it did that 2-3 times before starting and running normal. I felt like it had to "learn" something, I don't know. It's been running great but every once in a while, the thing will start, rev to 1500 (per normal) then just turn off within 2-3 seconds. I don't know why and it's not consistent, it may happen once every 2 weeks or something.

Well tonight, I ran to Home Depot then stopped by QT and when I got back in it, it started then died after a 1-2 seconds, this happened 5-6 times. I was stuck in the parking lot. Finally it wanted to run and I got it home just fine. It runs great other than this problem ever once in a while.

I also have a db-all connected via the OBD port, for my remote start range extender. I don't think this is causing anything but wanted to add that in the mix.

So, how do I troubleshoot? Should I try to log with the autocal every time I start, hoping to catch the problem? Would that even work? I'm not sure what else to try to diagnose the problem. Should I run the stock tune for a month to see if it's indeed the BB tune? Should I just email Blackbear? I don't know if it's mechanical, electrical, fuel... not sure obviously.

Any input would be helpful, thanks. It's hard to believe this "new" truck is acting up like this... my 2001 never had any trouble like this for 150k.

 

Yes. email Justin to confirm on his end

 

Any other opinions on this? I'm wondering if it's tune related or a mechanical issue. I'm going to email Justin right now and see what he thinks.

Another fun thing going on is that sometimes when I turn the key, all the lights go out and nothing happens, no start, no ticking, no flashing lights, just dead. Take the key out, wait a second, try again, most of the time it will start like normal, other times I may have to do that 2-3 times before it starts. I'm really hoping that I don't have a serious problem on a truck with monthly payments...

 

have you tried driving around for a week or two with the remote-start range extender pulled just to rule it out?

 

I haven't tried anything yet. It's starting to get worse and last night was the first time it happened multiple times in a row, during the same start-up.

I got an automatic reply from Justin saying that they are backed up and it could take awhile for a response, so I'll start with unplugging the range extender and seeing if it helps.

 

If anyone looks at this later, Justin has never seen anything like this before, during or after tuning. I also feel like it's related to the DB-ALL bypass module, that makes more sense.
Still not sure what's causing it but I double checked a few connections and it has it done it since (2 whole days). Time will tell, I haven't changed anything yet.

 

Albeit, now that I think of it... it's the transponder in the key talking to the igntion... saying it's "ok" for the vehicle to start

One or the other may need replaced

 

That sounds right for the "no start" issue and may also be related to when it starts and then dies. Something is telling it that it's OK to start and then that signal goes away, which is why I'm pretty sure it has to do with the bypass module.
This video shows what happens when I turn the key and nothing happens. I even hold it in the "Start" position for a while. I turn it on and off several times and then it eventaully starts.

20130121_083536.mp4 video by dnorman65 | Photobucket

 

Happened to our 2003 Grand Am... went to an automobile electrician... instantly diagnosed and fixed it. In our case it was the igntion... just swapped that out. No problems since.

 

I wouldn't think that my ignition is going out when I only have about 15k on the clock. But who knows...