98 V70 150K. For a couple of years I have had problems very infrequently with the engine cutting out and not starting. Initially, it only seemed to happen when it was below 20 Deg. F or when the weather went from cold and dry to warm and damp quickly. If it just wouldn't start and I left it alone for a couple of hours, sometimes it would start right up. On the humid days it would cut out and backfire, or it would start but as soon as you touched the gas it would die. Recently it got a lot worse. I listened and it sounded like the fuel pump was shutting off. I replaced the fuel pump relay with no change. I purchased a new fuel pump. Disconnect your battery before you do this! The access hole in a wagon is under the forward most storage compartment (in front of the spare tire)in the back. Four bolts hold the top cover on. Remove it. You will see the fuel pump access hole on the right side with bolts holding it. Remove it. Unplug the fuel pump and pry the fuel lines straight up and off with 2 screwdrivers or a pair of needlenose pliers with the ends wrapped in electrical or duct tape. There is a threaded bakelite cap which holds the fuel pump assy. in the tank. The best tool to remove it is a channel lock style oil filter wrench. The fuel pump I received had a bakelite cover which would not fit in the pump assembly. I very carefully cut it off the pump with a hacksaw. I had to re-use the original bottom filter, but it went in the assembly just fine. When I tried it, it started right up but would not hold idle and then died. With all the covers off I could hear that when the engine sputtered the pump was slowing down but not stopping. I unplugged the Mass Air Flow Sensor and it smoothed right out. I replaced the MAF and no more cut outs, but it still didn't start as smoothly as it should and didn't have much pep. Replaced the spark plugs with recommended ones. They were standard gap spark plugs and were properly set but the engine would not run with them in. Put the old ones back and it started. They were Volvo tri-arc plugs. I couldn't get them locally but found a set of Bosch tri-arc plugs that worked. I replaced the wires while I was at it. It starts and runs fine regardless of weather, although haven't had the real cold weather yet. I have kept the original fuel pump and relay as backups but hopefully won't need them.