EDIT: Just saw your other thread, seems you have confirmed good fuel pressure (yay!) and found other crank position sensor/distributor/dirty spark plug issues.
Odd that a faulty CPS signal wouldn't trip a code, but perhaps the intermittent nature allows it to be within acceptable parameters enough of the time to keep the check engine light off. Perhaps Mother Volvo is good about not "crying wolf" at the slightest issue, unlike some others.
I sure do hope all is resolved but if not, please consider that the fuel pump could be working intermittently.



mikebox, sorry for the late reply. I somehow missed this.

I agree with you and the other responses that your problem is indeed fuel related (especially if you have no trouble codes). I've experienced both a failed FPR and fuel pump with an 850 and the symptoms you describe sound like an intermittent failure of the fuel pump. On the 850 the car would randomly die or not start. Literally shaking the rear of the car or kicking the fuel tank would jiggle the pump enough to get it past the dead spot in the pump's motor and then it would run fine again. We confirmed this after replacement; applying 12V to the pump would make it run about half the time and shaking it got it running again.

Hopefully you can replicate the problem and confirm that the pump isn't running when it happens (jumper the relay terminals, listen for the pump). Otherwise I suggest checking the fuel pressure as others have proposed. IIRC when that went south on mine, it just ran like crap, really rich. Pressure would build then crash, repeat.


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XC60 / Odyssey