Volvo: Volvo 960 - Stalling, 1999 volvo 960, vacuum leaks

Question
We have a 1999 Volvo 960 with 100K miles (automatic) that has been running extremely well until the past few weeks. It starts immediately and runs great but after about 10 minutes of driving, it stalls out when I stop at a light or stop sign. There are no engine lights that come on and it starts up immediately. It may stall 5 times in a row and then not stall for the rest of the drive, or it will stall only at long lights, etc.  

We took it to our local guy who specializes in Volvos and other imports. He changed out the Idle Control Valve and thought that would take care of the problem. It didn't. He checked some other things out but couldn't find anything wrong. He also said there were no "messages" left by the computer which could help diagnose it.

Any help or thoughts would be appreciated!

Answer
Cate,
There are no codes to follow, so have your tech drive the car the amount of time under the conditions that you know make the car stall out using his fuel gauges on the car to see if it is stalling due to no fuel. If it is and the pump or pump relay is going out those do not leave any codes. There are some ground wires on the left motor bracket that if they are loose cause no start or stalling. Make sure the intake boot is in place and tight, no vacuum leaks.