Hyundai Repair: 2001 hyundai elantra start up problems, hyundai elantra, crank shaft

Question
I have a 2001 Hyundai Elantra.  I recently had my hood repaired and repainted. Maybe a coincidence but a few days later i started having trouble with my car in the mornings.  I would start it, it would idle rough.  I put it in reverse with my foot on the gas and it seemed to not want to go and then all of a sudden the gas would kick in and the car would go. It would be fine all day until it would sit approx 8 hrs and it would do it again.  I had the crank shaft sesor replaced this past Nov along with the fuel pump. I jus replaced thr spark plugs, wires and air filter. Not sure whether it could be oxygen sensor or what. Check engine light doesn't come on.  

Answer
If this occurs only for about 30 seconds or so after startup, Hyundai has a technical service bulletin (TSB) about this.  You're interested in TSB # 04-36-004.  According to the TSB, the vehicle may stumble on cold starts in warm weather.  The solution is to reprogram the engine control module (ECM).  If you're still under 80,000 miles, your local dealer should be able to reprogram your ECM under warranty for this issue.

You can view this TSB and other information at www.hmaservice.com.  You'll need to register for a free account, and the site requires Interenet Explorer.