Hi all.
So for some background, I swapped a 2006 engine into my 2003.
It ran pretty well, but I wanted to make the timing, duration, and rail pressure as close to 2006 stock as I could. I thought I did pretty well, but looks like I failed!
I had another issue with the truck, a failed transmission output shaft speed sensor, that was muddying the waters on my programming failure, so it was hard to nail down. Also, as unlikely as it seems, I swear the way the truck ran changed over time.
Initially I loaded in a 'as 2006 stock as I could make it' tune into the 2003. It seemed to run fine, had a bump in power over the stock programming and I was pretty happy.
Then one day it started to misfire above 2krpm with medium to heavy throttle applied.
Not suspecting the programming, I did a bunch of work to the truck. Then I finally set the ecm back to bone stock 2003 auto and the misfire has vanished.
So weird!
I'll be reviewing my program to see if there is anything obvious. I'd like to post it and maybe get some ideas as to why this has happened.
Chay