2008 Chevy Impala 3.5 Hard Starting When Cold


Full Member
Jan 12, 2009
Dropped the car off at the local GM dealership Monday after checking everything over myself along with the advice of you guys.
The only thing I could find was that the alcohol percentage on my code reader would still hover around the 74% mark while I still run only ethanol-free fuel. (The last tank was only 220 miles.)
Dealership mechanic “reset the engine control module, reset alcohol percentage readout to zero, and reran the idle calibration procedure.”
After 7 cold starts, it starts like it is brand again. Alcohol percentage has been a steady 1.2% over the last 125 miles. I’m on pace for 350 miles for this tank.
just wanted to follow up with you guys.
Thanks for the help.
Nick in WI