Hey guys, for what ever reason I decided to try and reset the timing. I wanted to bump the IP just a tad to take up for the timing chain wear and see if that did anything. well.. I almost thought I went in over my head when I attempted the TDC learn on GMTDscan. I got two codes, one of which I had forgotten I didn't put the PMD resistor back when I had to change the PDM on our last road trip, fixed that. the other was code 88-TDC offset error and the reading went to -2.02 without moving the pump any. it took me a few tries tweaking the pump back and fourth until I finally got it at -0.44 and the code went away. I stopped there since I was frustrated and freaking out all at the same time. Mind you I still have the OS bumped, have not put it back. there really isn't much info for the procedure setting TDC offset on pre 96 OBD1 trucks. anyway I think I had to move the IP maybe 2mm over toward the passenger side fender to get to where it's at now.
I know MrMarty51 mentioned advancing it near -1.43 for some better performance, I may try again soon, but I want to see how it acts where it's at now. I've attached both the before and after PCM snapshots for you all to help with any suggestions.
one other thing I saw while trying to move the IP, I found a barcode tag on the IP with a date code from June of 2010, not sure if that's good or not.
I also reinstalled the OE air filter housing and pulled that open Spectre filter since I saw my IAT's at 111 degrees and fuel temp at 116 with it idling in the shade with the hood open, outside air temp was in the mid 90's .
something else that came to mind that the truck has been doing lately is on first startup and when I take off down to road it kind of has a random misfire to is for a couple of seconds and goes away. it's been doing this even before I changed the turbo and the 4 injectors on that side, but since that was done it seems a bit more. the only thing is it only happens that one time when its been sitting all night or all day. after that it runs fine and wont do it again. could a fuel bleed back or maybe a small amount of air trapped somewhere do this?
let me know what y'all think about the snapshots, what could be better or done there, and about my weird random miss on first take off.
other than this the engine seems to run smoother than before I did the turbo, injectors, and intake gaskets. I'm also getting slightly more boost now, hitting 15 psi on takeoff with no load. seems to pickup speed better too! one plus I noticed so far is before with the AC running I could feel it lug when the compressor kicked in and out on the road, now I can barley notice it.