When our FFRR starts it runs rough, i'm guessing it is missing because there is a definitive smell of fuel out of the exhaust - on petrol & gas.

When the engine has been running on idle a few minutes it settle andirons silky smooth.

Also more throttle gives a smoother run - although on return to idle it'll idle rough again during the first 2-3 minutes

The roughness can come back if sat in traffic for a while.

I have a Carsoft i930 so I can take some readings if someone could point me what to measure?

*lpg not log

title edited for you  ... - .- -.




Y. O. L. O.
.

Cheers Stan

Any ideas buddy???

Is that just starting from cold or does it do it when hot..??? Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

So if we've been driving and turn the engine off then back on again it'll run rough again so yes it does it when hot too

The engine ECU richens the mixture on cold start for a while, similar to the old choke, mine smells of fuel if you stand at the back as well when this is happening..

I would imagine, for some reason, the ECU is doing this on every start... could be the coolant temperature sender is defective and showing it being very cold, this would make it too rich even on the first start......

Does the temp gauge work??

Try some live values from the coolant sensor, there are two, an engine temp and a radiator temp....  Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

The radiator coolant temp looks low.

I neglected to mention that when idle smooths out and you lightly touch the throttle for reversing or manuevering below 1000rpm it splutters.

After driving a short distance and issue is not occurring

Maybe a leak in the vapouriser which seals up when hot?

It does it on petrol as well

If it was a missfire you would have a MIL light on...

Yep, temp seems to be working OK, next thing is leaking injectors flooding the engine when you switch off, does it happen if you switch off and start again immediately...??

If your diaphragm is split it will run poorly on LPG, I take it it's fine on LPG...???

There are lots of things it can be, just covering the easy ones first....  Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

When I turn it off then on again it is lumpy straight away.
It behaves the same on lpg as it does on petrol

Check the STFT (short term fuel trims) with it running and see how far out they are, should be within + or - 10%

Also check the lambda sensors, they should swing between around 0v to 1v then back again....

I take it there aren't any fault codes logged...??? Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

I'm not sure what the short fuel trims will come under? I can't find them

Lambda sits at 1 then when rough goes up to 1.23 or 1.4, doesn't drop below 0.95

I cleared a load of codes yesterday- thinking I had taken photos of them all, then today I've had two camshaft codes come back