Volvo 850 2.5 power loss mystery

Was it misfiring or spluttering or giving any other such symptoms during the power loss? You;ll have to give alittle more detail for us to stand a chance at surmissing the problem!

Were you particularly low on fuel, any warning lamps come on, did the tacho behave strangely etc etc?????

Tim..

Further details are limited, I'm afraid. There were no strange noises, no warning lamps and the tacho reflected the revs correctly. The engine didn't misfire or stutter, it was just that for 15 seconds or so it was as if I had switched off the ignition (which I hadn't). I had refueled (with BP) 10 hours earlier in the day, but had only driven 3 miles since filling up. The previous day had been one of torrential rain, with puddles that I had driven through without problems, and this day had been dry, and windy.

Thanks again John Morris

Right.

Well your symptoms rule out both a faulty ignition barrel (common) and ECU power failure, and LT ignition switching- becuase the tacho remained indicating correct engine revs, but you were just coasting.

Therefore that does leave fuel pump and relay, and secondary igintion (this includes the amp, and coil). Both would be able to kill the engine dead wihtout any spluttering or partial power loss.

I'd check the connections at the coil pack, and the fuel pump fuse, and possibly get your hands on a new fuel pump relay (underneath the fuse box lid- 2 screws to remove) just incase it does it again.

If you are handy with a soldering iron, you can open up your exisiting relay and resolder all the joints instead.

Tim..

Thanks for the advice, I'll certainly try to get hold of a fuel pump relay, and will get the garage to check out the other items. John

Is this a 10 or 20valver?

Former is Single ECU Fenix and latter is dual ECU LH3.2 / EZ.

Tim..