Can anyone read the attached logs - attached as a photo. I have a downside O2 sensor fault but trying to understand if this is causing my starting issues.

half way down , i think the polygraph is saying that you are lying....



sorry i have no idea what all that means but someone will be along soon to explain..  ... - .- -.




Y. O. L. O.
.

Very good

Hopefully so, if it is what's causing difficult starting then maybe a new O2 sensor will do the trick.

Thanks! Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr

O2 sensors have little to no effect on starting... but knowing what FF's are like I'd eliminate all the errors you can find first....

Whats your starting issue...??? Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

My starting issue is as I have mentioned in my other post, difficult when engine hot. Fails at first attempt or splutters to start. I think it was you Pete that suggested injectors and I must admit it's sounding more like it - flooding due to wear/leaking. I decided to do a fault check and this is what came up with:
0x404 O2 sensor heater circuit bank 2 downstream sensor fault
0x414 O2 sensor circuit bank 2 downstream sensor

I also did some live readings to see if anyone on this forum could help. I do most of my own repairs but each one is a learning curve. Trying to find as much info as possible before spending more money.
(Sorry if I was wrong starting another thread)

Len Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr

Len,

My mistake, been away a couple of days.... I haven't got the IID Blutooth so not to sure what they are showing... lambda sensors should alternate between high and low constantly after the vehicle gets up to temp and the system goes closed loop... I think that's around mid 80's on a FF....

As I said can't see a faulty sensor effecting starting... maybe worth wipping out a plug next time it won't start and seeing if it's wet.....??

When you say it won't start does it just take a long time or will it just do nothing until it cools...??? Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

That's a wiring fault. Had the same when I bought Lucas sensors and the plug fell apart in a couple weeks. Wouldn't affect starting. 2004 L322 V8

Haylands wrote:

Len,

When you say it won't start does it just take a long time or will it just do nothing until it cools...???

That really does sound like the old Rover V8's when the injectors started to fail, never heard of it on our's but I suppose it's possible... maybe worth getting them checked.....  Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Just an outside chance it could be a bad connection,try removing any electrical connectors to the sensor and a little electrical spray .

I will try this when its dry (no garage) - might at least save my buying a sensor needlessly.

And main stealers want £169 + vat  Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr

Rangeyman wrote:

Just an outside chance it could be a bad connection,try removing any electrical connectors to the sensor and a little electrical spray .

Lenb wrote:

And main stealers want £169 + vat

They are Bosch ones, I got a vehicle specific one from a motor factor for about £40... I do get trade discount but it should still be much cheaper.....  Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

The downstream O2 sensors (B1S2 & B2S2) have no effect on running of the engine. They are merely there to check the efficiency of the CATs. Once the CATs have warmed to their operating temperature and the system enters closed loop the downstream O2 sensors should show a fairly steady graph with very few spikes (it will move with rpm/load changes). If the downstream sensor matches or oscillates wildly like the upstream sensor then it indicates the CAT is doing little or nothing to the exhaust gases (assuming it's warmed up, older CATs may take longer or higher revs to get hot enough to work).
If the downstream O2 sensor is flat line all the time it indicates a possible fault with the sensor, either the sensor itself or it's heating circuit could be an issue. The wiring then needs to be checked at the sensor before condemning the sensor itself.
Again though, it has no effect on the running of the engine, the downstream O2 merely report CAT efficiency and flag an error if outside the limits.

I assume the graphs are Upstream and Downstream O2 sensors? It looks like that was with the engine warm? In which case I can't see an issue assuming the oscillating traces are Upstream and the more uniform traces are Downstream.
It could be an intermittent fault that has thrown up the O2 codes.

As for your hot start issue, as you suspect and has been mentioned by others, it most probably indicates a fueling issue (over or under fueling due to injectors or supply issue) or possibly electrical with a component breaking down under heat soak (crank sensor) although I would expect it to also fail when running and hot (stalls) and would also hopefully give error codes. For that reason, and it's fairly easy, I would be checking fueling first.

I would check fuel pressures on hot start to rule out supply problems, if it checks out (compare to cold start, just turn the ignition on and compare how quick they reach max pressure) then use a scope to check the voltage trace of the injectors to see if they are firing correctly.
Cheap and dirty, hope and pray but wont hurt, run with some injector cleaner for awhile.

Weejock - thanks for the explanation re O2 sensors. The graphs are just Bank 1 Lambda Control & Bank 2 Lambda Control - and its bank 2 that's coming up as a fault, which is also the bottom graph, (from the drivers seat, which is bank 2?).

I have put in some injector cleaner (after all there is nothing to loose) and next week I will be checking the fuel pressure - will update when I know more.

Thanks for everyone's help so far

Len Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr