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Sorry , just remembered I did a full service oil filter plugs etc as the oil was like funk

ph001 wrote: ↑Tue Oct 24, 2017 10:02 pm No, if it's turning over ok it's not likely to be either of those. I'm assuming you have enough fuel in, in which case fuel pump / fuel pressure related maybe. When did you last fill up?

When you switch the ignition on, can you hear the fuel pump priming as normal?

Not true.

When my ignition switch failed it would turn over but not fire. Position 2 was intermittent and unless the ignition lights came on it wouldn’t fire. Not something you tend to notice when you just get in and turn the key.

srhutch wrote: ↑Wed Oct 25, 2017 9:17 pm

ph001 wrote: ↑Tue Oct 24, 2017 10:02 pm No, if it's turning over ok it's not likely to be either of those. I'm assuming you have enough fuel in, in which case fuel pump / fuel pressure related maybe. When did you last fill up?

When you switch the ignition on, can you hear the fuel pump priming as normal?

Not true.

When my ignition switch failed it would turn over but not fire. Position 2 was intermittent and unless the ignition lights came on it wouldn’t fire. Not something you tend to notice when you just get in and turn the key.

Good call, just that the OP said it started, then spluttered and stopped which suggests a fuel issue rather than electrical. Anyway, glad it's sorted.

OP- did you by any chance start the car briefly from cold to move it for example and then switch it off again? You can occasion get something called bore wash whereby the rich mixture washes away the oil film in the cylinders resulting in poor compression and lack of starting.

I've never heard of the issue on the Z4 though.

As normal , I tried to start it @5.00am to go to work , it spluttered and cut out straight away

It actually sounded like a cam belt had snapped/no compression as it spun quicker than normal

That sounds like bore wash alright, but normally it would have to have been started from cold the night before, run for a few seconds and switched off again.

If you get a reoccurrence of this it undoubtedly needs looking into further.

The OP reports the car starting but spluttering to a halt from cold and has three codes relating to O2 sensor reading being too lean / out of spec. Going with the symptoms and info the car is giving this logically suggests either O2 sensors are down causing bad fuelling OR or there is a vacuum air leak on the intake side causing over-lean fuelling or metering. Its an M54 engine which is famous for split hoses and boots around the intake system and MAFF so that's where I would start first, hopefully it will be a cheap fix

funny one, cars perfect since my last post above but battery light came on today,drove home and put a meter on it 14.5v which is a charging alternator.I scaned with obd and got the original codes again p0160,p0161p2234 so i cleared them and went to restart it.First issue all over again in that car wouldnt start,i did the flooded procedure with full throttle and it started with battery light gone.

driving fine since, very weird,ill look for split boots as suggested above but batt lite is odd ???

zaga

Just put a new set of plugs in mine. Made a great difference on starting.
Thing is and always has been is. If I get in and just turn the key it will crank for about 5 seconds and then start.
If I get in and put ignition on then seatbelt and then crank it will start straight away.
Was thinking it was a priming of the pump type thing.

Ewazix wrote: ↑Thu Oct 26, 2017 7:20 amThe OP reports the car starting but spluttering to a halt from cold and has three codes relating to O2 sensor reading being too lean / out of spec. Going with the symptoms and info the car is giving this logically suggests either O2 sensors are down causing bad fuelling OR or there is a vacuum air leak on the intake side causing over-lean fuelling or metering. Its an M54 engine which is famous for split hoses and boots around the intake system and MAFF so that's where I would start first, hopefully it will be a cheap fix

O2 sensors are ignored at start up.