intermiitent cut out
 

Ok, so i've had my S70 T5 back on the road for 8 months following an engine change and rebuild/overhaul. Driving along the other day (slowly in traffic) and it cut out and rolled to side of the road (right in middle of busy one way system which was fun). I then tried to re start, nothing, after 5 attempts it fired up and off I went. When trying to start it started and then stopped within 10 seconds. any ideas? Fuel Pump maybe? its not my main car but I do need it reliable. After then I took it for a nice long drive and no problem, used it to come to work today and had a slight stutter coming out of a junction and then fine again?? Its had new fuel filter and I did fit new starter relay and secondhand fuel pump during rebuild. No fault codes shown

In my experience if the fuel pump dies then it won't start at all. Personally if you had it apart I would have fitted a new one, I have had to replace a 2nd hand walbro after it died in an ASDA car park...

You can test for fuel at the rail by using the schrader valve. You can test the fuel pump by removing the cover and giving it a 12v supply.

Another possibility rather than the pump is the fuel pump relay (located underneath the top section of the windscreen fuse box).

With it actually starting and then cutting out to me it sounds more like a sensor is on it's way out - possibly the MAF sensor. When it started (and before it cut out) did it run fine or was it a bit rough? Any smoke out of the exhaust?

Check the battery connections, I had random cutting out which turned out to be a loose connection of the secondary positive cable on the top of the positive battery connector.

Intermittent Cutting Out
 

No, there was no smoke or rough running, in fact running like a dream. it felt like it ran out of petrol so will replace the pump and relay for good measure. I have also now invested in some breakdown cover!

Hi S70Smith

What year S70?

Steve

Hi S70Smith

If you can hear the fuel pump buzzing briefly when you first turn on the ignition, I wouldn't immediately suspect that (or the relay).

Steve

I know a dodgy MAF sensor normally throws an EML up, but have you got a spare one you could try?
My old 2.5t started doing this. I replaced it with an aftermarket item from ebay, and it cured it.

Intermittent Fault
 

Hi its a 1998 so throttle cable, no I don't have a spare to try sadly. I drove it home from work last night and all fine, tried slow driving, fast driving, every style and nothing ran like a dream. I kinda wish it would either break down or disappear (the problem). As you say the fact it runs fine 99% of the time doesn't point to fuel pump as I assume they work or don't!

I think it's deffo fuel pump relay. Had it years ago with exactly the same symptoms, cutting out when driving and would then restart say after 5 mins when its cooled down. A cheap n easy to replace part !

Cheers

J.