Rough Running While Cold
12-08-2009, 05:56 PM
#1
Rough Running While Cold
When my car is cold it will run rough. The wide band indicates it is going from way rich to way lean. the meter maxes out at 10 and 16. Is this normal? The problems clears up once it is warm. Thanks for the help.
12-08-2009, 06:31 PM
#2
6th Gear Member
Join Date: May 2006
Location: Nicely done
Posts: 11,881
upon cold start up, the vehicle is in
open loop mode. that means it does not
use the o2 sensors to attain a specific
a/f. i believe the pcm uses values from
tables in the tune, until the o2's are
warm enough to provide a stable voltage.
open loop mode. that means it does not
use the o2 sensors to attain a specific
a/f. i believe the pcm uses values from
tables in the tune, until the o2's are
warm enough to provide a stable voltage.
12-08-2009, 10:47 PM
#6
4th Gear Member
Join Date: Jul 2007
Location: Houston TX
Posts: 1,474
i have the same issue ever since my whipple install. Mine is a custom dyno tune. Happens when my car starts in the morning, and i drive off, the car would sputter for like 3-5 secs, then drive normal. The rest of the day, its perfectly fine.
12-08-2009, 10:59 PM
#7
2nd Gear Member
Join Date: Jun 2007
Location: AZ
Posts: 412
Since I got my bamachips race tune, during cold weather only (40ish and below) my car will run a little rough at startup. It will start, run rough for a second or two, then run around 1500rpm for a few seconds, then return to normal and will be good to drive. Since it only happens in the cold I just figured it was a temperature related issue and nothing to worry about. I'm sure you have nothing to worry about as well.
12-09-2009, 12:59 AM
#8
2nd Gear Member
Join Date: Aug 2008
Location: san antonio
Posts: 375
same here, Its like it starts and is really loud (neighbors hate it), sputters a little, settles sometimes until I take off and it wll go away for the rest of the day.. Im running a tune also not sure if its related to that...
12-09-2009, 10:28 AM
#9
2nd Gear Member
Join Date: Jun 2007
Location: AZ
Posts: 412
My best guess is that the tunes we have cause the engine to go really rich at startup (can sometimes smell some fuel,) which on a cold engine may lead to the sputtering. It then speeds up to keep itself running until everything evens out.
12-09-2009, 03:07 PM
#10
Join Date: Nov 2007
Location:
Posts: 15
I haven't installed gauges yet so I am not sure what my a/f is but after I installed my e-force the car idles way high at cold start up (like 2500), which it did not previously do, then slowly creeps down to normal after a minute or so. I called brenspeed and they did not think it was anything to worry about, just said it is in open loop mode and trying to heat up the sensors as described above. Mine does not idle rough though, just higher rpm.