Fighting with similar issues after a dod/afm delete using another companies low lift cam. Shitty idle, strong cat converter smell at idle (burnt hair smell), low vacuum (map sensor codes, service brake message, etc), and p0300.

Still working with my tuner but im pretty close to pulling the cam out and putting a stock non afm 5.3 cam into it because im afraid its just too much cam or the 112lsa just wont work with my setup. 2008 suburban

 

I re-measured, this time I set up directly on the push rod and took the valve spring out of the mix. The cam measured perfect. Tonight I am going to swap coil packs and plug wires from the drivers side to the passenger side to see if I can rule out a coil pack issue.

 

Mine idles perfect, no codes. I am leaning more towards a hardware (coil pack, plug wire) issue due to it was running good on the +16 degree tune Friday and after having the valve cover off over the weekend it won't run good on any tune.

 

OK, good to hear.

 

interesting, keep this going please

 

Will do!

 

If the problem was on only one side and you put in +16° timing won't that make the other side of the engine WAY advanced? I am also curious about it not working now with the +16° tune just from having the valve cover off......I agree it sounds like a hardware issue.....connector or wire in the coil harness? But why would that make it ignite late? I would think it just wouldn't fire at all.....

 

I swapped plug wires are coil packs last night. This did not change anything. The last thing I have to check is push rod length and possibly swap injectors if you guys think there is a reason to try that. I still feel as though it is something with torque management in the tune, only because it is fine at idle and fine cruising. This morning for example it would act up at tip in through first gear, act up through 2nd gear and be fine in 3rd-6th.

I also tried my bone stock engine and trans tunes that I shut off vvt and DOD and associated fault codes.

Does anyone have any other ideas?

 

What is also weird is with the +16 timing I would only get 1 or maybe 2 degrees retard due to knock and that was not consistent. Justin said the tune had advanced timing to begin with. I checked the connectors and did a quick glance over the harness last night when I was swapping the plugs and coils and didn't see anything obvious.

 

So always 1st and 2nd gears only? That IS bizarre.....