Speed Density Tune + Cold Weather
#25
TECH Regular
Join Date: Jun 2004
Location: Edmonton, Alberta, Canada
Posts: 447
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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.
#26
TECH Veteran
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.
#27
TECH Fanatic
iTrader: (10)
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.
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.
#30
TECH Fanatic
iTrader: (10)
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.
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.