LPG tuning

How do these live data shots look
On petrol both banks-%
On gas one -% one+%
Also note trans idle at top of screen
Runs ok on both fuels slight drop in power but have a low idle on petrol sometimes cuts out don't know why maf has no reading tried 2 on it still reads the same it's a snap on ethos scanner any tips will try post live. Data

Lpg

Petrol

LPG software

That shows me that the person who set up the LPG either couldnt be bothered or didnt know how to do it...
It shows that,(Assuming it has been run on gas for a while to go through all its drive cycles) bank B is feeding less gas so the engine ecu is widening the injector pulse width to get the oxygen sensor cycling on that bank.
That the LPG software shows all the settings on -15 tells me that a basic autocalibrate was done then there was a blanket -15 trim added after.This one size fits all setting will not make life easy for the engine ecu,making the long term trims unsuitable for both fuels and lead to the problems you have now.
Is the latest software in the scanner,the most recent variant is way better than the old versions.

It's 11.4 software on ethos what's the best way to adjust the LPG settings? There didn't seem to be options on my laptop for it either that I couldn't see it.i like doing stuff myself so would like to DIY it if possible a y ideas why only one bank is doing it? Also the big difference in trans step? Could it be an air leak at LPG nozzles as seems to be ok on petrol thanks

If you click on the individual numbers on the trim page you should be able to edit them,click enter after you input each number to set it.There also should be another page which from memory is the one where you set the number and type of oxygen sensors.On this page there is often a box where you can use an offset,+ or - up to 20% on one bank.
To do this properly you need an empty road,an understanding helper to drive EXACTLY how you tell them - and then drive the car on petrol while watching the petrol trims at each of the settings for the boxes on the trimming page.Do each one,starting with idle,note the fuel trim on petrol then switch to LPG and alter the numbers until you get the short trim value on the snap on scanner to read the same as it did on petrol.Repeat this for all the boxes and you have a car whose adaptive trims have a fighting chance of working well.(And doing what 90% of LPG fitters fail to do...)
Its not hard,just remember that the LPG kit is not as well made nor accurate as the petrol system,so dont be too fussy - in the parish is WAY better than what you have now.Good luck and enjoy how much better your car will run when you have finished.

Thanks for the info my setup doesn't have the 02 sensors wired into it,would this make a difference?i stripped the LPG injectors today and cleaned them ,but were clean anyway,they are valtec ones.would adjusting the offset correct the imbalance between the 2 banks?all the boxes are at -15 to richen it I guess would go closer to 0 and to lean it would go further - value.would the pressure from the vaporiser need adjustment sitting around 1.1 bar.this is very helpful as I like to understand how things work and diy ing instead of just putting into a garage and getting fixed .thanks

dove said:

Thanks for the info my setup doesn't have the 02 sensors wired into it,would this make a difference?i stripped the LPG injectors today and cleaned them ,but were clean anyway,they are valtec ones.would adjusting the offset correct the imbalance between the 2 banks?all the boxes are at -15 to richen it I guess would go closer to 0 and to lean it would go further - value.would the pressure from the vaporiser need adjustment sitting around 1.1 bar.this is very helpful as I like to understand how things work and diy ing instead of just putting into a garage and getting fixed .thanks

Click to expand...

Your setup wont need its own oxy sensors,it just uses the pulse width of the petrol injectors,(Which you can modify via the trimming page of the LPG software) to output to the LPG injectors.Try altering the offset to one bank,you will soon realise which way you need to go in order to balance it up.TBH I'd have to look at the individual system to see what you need to have for it to work well in terms of vaporiser pressures etc.(LPG was alot more common locally about 5 years ago - seems to have dropped out of favour now to TD5/6 and TDV6) As long as the oxy sensors will stay rich with a wide open throttle you have enough gas pressure.
Just fiddle around with the settings till it works right,I had no training at all with LPG,just got loads of poor running cars dumped on me to sort out.Most just need careful setting up, up,at least an hour of driving and tweaking,even when you know what to look for.Owners were often very suprised at how well their cars could run on LPG after a tweak.

Ok thanks will try it soon,and repost my results ,thanks again for your replys