I have a 2004 XC90 6 cyl turbo that I bought used roughly 6 months ago. Exactly a month ago it would start but cut out 15 seconds or so later. Had it towed to a local shop who diagnosed it has being a crank shaft position sensor problem and $1000 layers all appeared well. Well yesterday I started having similar problems. First thing in the morning it started just fine and ran a few errand with no problems. Mid-day as I was leaving the grocery store parking lot it acted like it wanted to quit but I gave it some gas and off I went. This happened twice. The third time we were attempting to go fishing and it would turn over but wouldn't stay started. This morning it started no problem and I drove it for 6 minutes to a gas station (I even timed it). Left the gas station and it wouldn't stay started. Call a tow service and roughly 1.5-2 hours later when the tow truck showed up the man had no problem starting it and keeping it running. I initially thought fuel pump but the tow truck driver disagreed and suggested maybe a bad fuel injector. That got me doing a little more research and I think I've narrowed it down to either a fuel injector or the ecm/ecu. Am I on the right track? I realize it could be a million things but I'm trying to do what I can before spending thousands more at an auto repair shop.

 

no way you can tell without some additional tests. One test would be to measure fuel pressure prior to starting and then after running. I would also check and see if any fault codes were saved. Not sure how somebody can simply say its not the fuel pump... Not sure about your model but this can be caused by a fuel pump relay, a fuel pump, a fuel pressure sensor, fuel pressure regulator, a fuel injector relay just to list a few possible items. The XC90 ECU problems seem to be more with the car dying while driving, not starting up. ECMs usually throw fault codes when they fail (ie communications errors as it can't talk to other devices). You can try removing and cleaning the contacts with electronics cleaner then reseating it but it doesn't seem to match your symptoms. Personally, I'd be looking at fuel pressure and delivery issues.