My Volvo was stalling randomly and I was almost certain that it was the crank position sensor. After changing it I let the car idle just to make sure that it was the CPS but it stalled after 5 minutes of idling. It starts right up most of the time but the same thing happens, the car stalls after idling for approximately 5 minutes. I checked the radio suppression relay and fuel pump relay with a 12v transformer and both work fine and have continuity. What else could be causing this problem?

 

I had a similar problem a few years back; turned out to be crud in the tank. When the engine started, it would suck the stuff up to where it plugged the sock at the fuel pickup tube after a few minutes, killing the engine. After the car sat for awhile the crud would settle back to the bottom of the tank and the car would start again. Hopefully this isn't your problem; cleaning fuel tanks is kind of a PITA..

 

Thanks for you suggestion. When I have time, hopefully this weekend, I am going to open the inspection hatch at the trunk and check the fuel hoses and connections, fuel pumps and wiring, and I guess now the fuel pump sock. If I am right, I have pretty much narrowed the problem to that area of the car. Ignition, vacuum, codes, CPS and relays all check out good and the engine, when it runs, idles smoothly and without problems.

 

Any codes? If not, I would change the fuel relay and make sure the fuel pump is OK. Somehow I am not too confident in the "transformer" checks...