My 2006 civic is currently in the shop, they can't find anything wrong. It has a fairly new battery, 8 months old. 4 times in the last 2 weeks I have been unable to start my car- had to jump the battery. I had the battery and alternator tested at 3 different places, including the shop where it is now. They kept it overnight , but the car started fine this morning. They did a full electrical diagnostic but were unable to locate a problem. Any thoughts. Anyone else with a similar problem find a cause?

 

Diagnostic flowchart for a car that won't start or stalls - Troubleshooting for the starter, spark failure and the fuel pump