That's poor business by them if you ask me. It is impossible to just slap a calibration into a PCM, mail it to someone and have it be 100% perfect for their setup. If that was really the case I'd turn this stuff into my day job lol.

Mail order tunes are there to get it started and to get it up and running. How are they to know the exact fueling needs at any given time and at any given situation. You can't rely on the computer to compensate for everything as there are far too many variables between setups, climates and fuels used.

I've never dealt with a Nelson tune before so I don't know how they do things. Surely someone couldn't just tell me they installed a LS6 intake, 212/218 camshaft, long tubes, 42lb/hr injectors and whatever else, then have me just plug a few numbers into a tune and call it good. It would take hours on a dyno or street driving to get things in order. I'm not a pro but I've been tuning things for over 8 years now so I've got the basics pretty much down.

 

I got my injector harnesses from Glenn’s Auto Performance, and I’ve got no complaints, for what it’s worth.

 

Went to swap out CMP sensor and as I was pulling the air inlet elbow I found that the backfiring through the intake caused the throttle blade to look like a taco. Which would explain the high idle issue. Luckily I ordered an OEM TB so I took the blade off that one and cleaned it up and installed it on the ported TB. All back together and starts right up and runs decently normal. Still seems a bit rich but Im going to put some drive cycles and mileage on it to break in new motor. More to follow...

 

Wow lucky it got the butterfly instead of blowing the plastic intake manifold out to pieces! Glad you got things sorted out... should be a strong n/a combo.

 

Just another quick update... found 3 spark plug wires torched (through plug wire socks) to the point I'm sure spark was jumping to header. Replaced with straight plug boot wires temporarily, but have 2 sets of 2500 degree socks, with SEI header spark plug wires that will go on after engine break in oil change, along with another new set of AC Delco Pro Series plugs. Gap for 2003 6.0L says .060" and 2004+ LQ4 says .040" What are you guys running? 40? 60? Or do I split the difference and gap at .050"? (Also codes being thrown are down to two, Bank 1 S1 and Bank 2 S1 Lean)

 

If those are Iridium plugs the gap should be pre gapped at .040 carefully check the gap and don't fk up the small wire trying to change the gap. With a roll of the dice mail order tune throwing lean codes... my advice is to install an AEM wideband (30-0300 X Series) to monitor the air/fuel mixture. After all the work and money you don't want to toast the motor now. I've dialed my tune in spot on and still keep an eye on WOT hits (12.5 air fuel ratio) making sure nothing has changed the air/fuel mixture.

 

Dyno tune scheduled for next Friday. Break in mileage done, all fresh fluids and 3.73's and posi in the rear end. We'll see what my science experiment lays down on the 24th.

 

Dyno and tuning complete. Made 380rwhp and 390rwtq. Definite improvement from the V6.