Ok, ill try to get ahold of KBracing. I'll call the dealer and have them check the fuel pressure as well.

 

Man I wish you where closer, I'd fix you up! Rock Springs is clear on the other side of the state about 4.5 hours from me. And it is DAMN cold here!

If I can help you, let me know! More then happy too

 

Do you think a whole new tune for up here would help? If thats what I need to do then thats not a problem.

 

Also is NorCal with SD tune. Driven with it from the low 20's to over a 100 degrees. It always seems to run fine.

Rick

 

Went SD about 4 years ago now on the Denali. The tune was done by Nolan at Campbell Automotive here in Edmonton. Has worked great all the way from -40C to +40C.

 

I certainly wouldn't go putting a maf back on it. Aftermarket maf or stock the pcm limit is the same for airflow calibration. From there you can only alter the p.e. which puts fueling great if you only drive in vacuum and full boost. Anything in between will be richer than needed. Most likely the problem is in the injector calibration. Minimum idle air could be a problem as well as a few others, but I usually find this problem to be in the injector calibration.

 

Hope you've found your trouble. My truck was acting exactly like yours after a spark plug change. Thought it was a bad plug. Changed plugs and the same thing. Pig rich at idle. Rough idle. Runs better if you can get it up to speed.

Decided to look for other issues under the hood. I noticed the boost was low under moderate acceleration. HMMM. Usually see 4 to 6psi. Not seeing much boost, but the truck ran pretty good at speed. Decided to check vacuum lines. Found a split "T" (pretty good vacuum leak) where the boost guage tied in. Haven't fixed it yet, but I bet there lies the problem. Butt freezing cold temps have to be pretty tough on lines under the hood. Might be good to check yours.

 

Tuned mine OLSD in 85 degree weather this summer, its been down to 20 now and its doing just fine.

 

I'll check the lines when I get back down to the dealership again.

 

Fixed it this afternoon and that's exactly what my problem was. We must have jerked the line around too much during the spark plug change. It doesn't take much of a vacuum leak to make it run like ****. I took the T loose completely with the engine running and it died immediately. Hope yours is that easy and cheap to fix