Yeh I wasn't being funny ians, was trying to prevent a wasted trip.

Most code readers tell if you the vehicle is running closed loop on each bank, they'll say something like bank 2: CL (closed loop), and then if you can see lambda voltage flicking between 0 and 1 volt (or lambda flicking between just below 1 and just above 1 if lambdas are wide band) and fuel trims are a reasonable figure you know the engine is running ok closed loop on that bank. It may be that 'oxygen sensor bank 2 active' with your setup means the same thing but you should check, because never know this could just mean heater circuit checks out ok on your reader.

There are no flaps inside that manifold but there are internal pipes inside it's inlet port runners, these just carry air. If the end of a spud is in one of those pipes then gas isn't going into the main airflow and that will cause problems. If a spud is fitted too high, then when the engine is idling the gas injected from the spud won't be mixing with air going through those pipes so again will lead to problems. I know through experience that on this engine some thought has to be put into where to fit spuds, particularly on 5 & 6, because the petrol rail bracket slightly obscures position where you'd like to drill on one port runner and there is a raised bit of strengthening plastic on the other.

The BMW might not immediately run properly and closed loop if it has recently been forced to run open loop due to a problem, but it would be worth seeing if you need a new probed before you come if you can.

Simon

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Hi guys
Simon I didn't think you were being funny.... I completely get that there is no point in you working your magic if there is something inherently wrong with the engine and I'd rather have that side of it right for when you see the car
I'm struggling with the electronics side of this.... The last petrol car I had was an 83 Renault 11 turbo and that had literally no engine management at all since then I've had diesel and if something was wrong the code reader told me what to change
The code reader I'm using is an autel mot pro that has a BMW specific program.... I'm wondering if I put it onto obd scan and read it if I'll get the open closed question answered
Fuel trims.... On petrol they're all pretty close on lpg cyl 6 is out

Manifold... I wish I'd taken pics last time it was off but if I need to I'll pull it off again at the weekend (easy job compared to the diagnostics)
If memory serves me correctly the internal pipes have little plastic caps on the end of them (they tend to drop out when putting the manifold back) if I'm remembering correctly then the lpg nozzles are close to the actual fuel injectors and not touching these secondary air pipes.... The nozzles are brass ones that have been drilled and tapped into the manifold... Looking at their location I can't see how they could have been put in without removing the manifold and injection rail
If needs be I'll pull the manifold off this weekend and photograph the nozzles and add them to the Dropbox folder I shared earlier

You should find some sort of section called i/m readiness - or something similar. This should show your open/closed loop status in a simple to understand way.

Yup I know that's definitely on there in the obd section
Looks like using the BMW specific features was a bad idea

Ok i've just spoken to the manufactures of my diagnostic tool ..... they weren't much help
i'll run an i/m readiness tonight and see what it says
from what i'm reading on my fuel adaptions and o2 readings that bank 2 pre-cat is heading on its way out
i'll swap both at the weekend whilst pulling the manifold off to check the nozzle sites (apologies if i'm using the wrong terms)

Might be worth swapping the sensors over rather than buying another one - if the fault follows the sensor you know its shot, if it follows the bank you know theres an issue there.

oooohhh thats a good call never thought about that ..... done it with coil packs and plugs never thought of doing it with the lambda

IM readiness doesn't usually tell you if a cylinder bank is running closed loop or if a specific lambda probe has passed IM readiness though. Best bet might just be a generic scan tool that shows live data. Or readings from LPG software screen can help determine that, especially if it's known that the LPG ECU is connected to the probe or LPG ECU can read live data via OBD, but this can take some reading between the lines. Starting to wish I hadn't mentioned potential for B2S1 being down, won't take me long to dis/prove it when you come. Why not buy one but keep it unopened in the bag, change it when you come if need be or take it back unopened if not?

Simon

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07816237240

Evening all
There is an o2 monitor section in the obd part of my reader that shows OL on both sensors when you start the car and after a couple of minutes they both change to CL
Which I think answers the question I've been looking for
In your last post Simon you answered the question I haven't asked... Do I change the sensor now or wait till you have the car? I'm going to wait till you have the car

I'll pull the inlet manifold off this weekend and photograph the spuds unless I manage to borrow a boroscope to do it that way
Apart from that is there anything else I should do before I bring the car up??

CL is good.

I wouldn't even pull the inlet manifold off, it's a bit of a pain, and I know what spud positions work anyway.

Simon

_________________
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07816237240

Dammit that means I have to talk to the Mrs this weekend unless I can find another car to play with

hey everyone
I'm pleased to say that swapping lambdas proved that there was a problem with bank2 lambda
apart from that there isn't much to add to this thread until i take the car to simon

What was the difference when you swapped lambdas mate?

Simon

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hi simon
misfire went from cyl 5/6 to cyl 1/2/3 idle was awful and it hated running on lpg so much i switched it off
put a new one in and it's a different car
still bringing it up to you though because I'm not convinced the lpg is calibrated correctly and it may need other things

No probs Ian. Seems like the main problem, broken lambda sensor, has been sorted now which is good news! Does it run OK on LPG now, misfires gone?

Simon

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yeah the misfire on hard acceleration is gone ..... the cutting to petrol under hard acceleration is new though lol
if i run it gently its pretty perfect but not completely

Sorted today

Problems were due to a combination of issues.

3L BMW straight 6 which doesn't need a valve lube but a lube is fitted. The lube nozzle isn't a proper very narrow gauge lube nozzle, it is just an injector outlet spud with 3mm internal diameter, so lube droplet size would be massive and lube wouldn't atomise properly... even if the nozzle was in the correct location just after the throttle body, but the nozzle is fitted just into the upper plenum area. Actually any lube system on this engine (if it needed a lube) should be multipoint because the engine features idle-air, with any lube other than multipoint on this engine while the engine is idling the lube will just be dripping into the vacuum of the plenum and pooling. The 6cyl engine in X5's slopes down towards the back, lube was pooling towards the rear of the plenum and richening the rear bank of 3 cylinders. I turned off flow of lube, to allow the pool to clear in time, because this engine doesn't need a lube and because of all of the lube issues.

Previous issues with the LPG system, failed lambda probe and lube system had caused the petrol ECU to learn incorrectly, fuel trims were way off combined with a bank trim issue and BMW 'smooth running' values (which are like a mini fuel trim for individual cylinders) were all over the place, particularly affecting cylinder 5. The petrol ECU couldn't complete IM readiness so long term fuel trims were stuck at -8.5% on both banks but stfts were maxed out on bank1 and minned out on bank2 due to too lean LPG calibration, incorrect LPG map shape and the lube issue. System was calibrated with too much pressure (1.4bar) with multiplier of less than 1 over most of the map and idle ginj of only 3.7ms with 70c gas vapour , I re-calibrated with well suited map shape at 1.1 bar.

Following the changes I made we ended up with an engine which idled and drove perfectly, ltft's still at -8.5% on both banks and stft's of +8.5% on both banks at idle on either fuel and close to zero off-idle. The petrol ECU will now complete IM readiness and the fuel trims will all be steered close to zero, hardly changing on either fuel..

Reducer pressure isn't the most stable and was falling a little below the changeback pressure that the installer had set (or more likely hadn't bothered to adjust in the first place). Following my changes the vehicle will drive totally on gas at full throttle up to the red line, and though ginj approaches 100% duty cycle mixture remains rich at full load. The vehicle was switching back to petrol during the over-run, I sorted this by changing rpm setting from cam sensor to petrol injectors; with the petrol injector setting the LPG ECU doesn't change back to petrol due to lack of rpm pulse detection.

All fixed That's 3 vehicles with long standing problems each coming from many miles away sorted today..

Simon

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Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240

As Simon has said... All sorted... From a driving point of view we left Simon's yesterday and drove to Peterborough then back to merseyside all in around 300 miles
The X5 didn't miss a beat and despite some "spirited" driving she still managed 260 miles to a full tank of lpg

I would highly recommend Simon to anyone looking for an installer he genuinely goes through the problem and takes the time to explain his findings and recommendations to the customer

Simon.... Darren says he'll be in touch about the kit for his astra when he's got the money saved

Cheers Ians

I'll look forward to hearing from Darren.

Regards, Simon

_________________
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240