Alright,

Just been playing with my ODB2 scanner to see if I can nail down why the D/S bank makes a 'plodding' noise when on LPG and just wondering what the trims/advance should look like when driving along?

The long term trims sit at about -13.4 each whereas the short seem quite sparadic? Sometimes one on -3.5 and other +3.5?

Also my timing advance says between 25 and 35, is this normal?

Sorry if this is in laymens terms, I don't pretend to know what it all means, just mechanic suggested knock sensor is fried.

Regards,

Diehard

All normal,esp when the poor thing is confused with a poorly setup/functioning LPG system.

eightinavee said:

All normal,esp when the poor thing is confused with a poorly setup/functioning LPG system.

Click to expand...

Well I'm hoping its not poorly set up as had new injectors two months back, new filters and all re-calibrated... and the once more due to a bad earth, also MPG is about on par with others... I.e. I didn't fit it if that's what your getting at

No,not at all.Its just that I rarely see LPG converted cars that run properly.Very little attention gets paid to accurate trimming of the LPG map to try to mimic as closely as possible what the petrol ecu would be doing,(And receiving feedback to confirm it from the oxygen sensors) under the same conditions.
There are two ways to do it,first is a rolling road,which is nice but expensive and not easy to access.Second is to have the LPG software running in the car alongside Testbook or similar showing the live data from the engine ecu.You need an assistant to drive the car on a quiet road where you can drive at speeds which you choose.Make notes of what it does on petrol at certain speeds/throttle openings.Then switch to LPG and trim the LPG ecu to get as close as possible to the petrol readings.This can take up to an hour of fiddling around,but makes a huge difference to how they run,customers often comment that they can no longer tell the difference which fuel they are on.
It takes time and effort,most techs seem happy to get it 'near enough' - which is why so many end up with problems.

Ah no worries, I appologise

Well when I had her done the guy sat next to me with his ODB tool and watched the trims (this is after an auto calibration) and we had a little drive. He made a couple of minor adjustments (to the LPG lamda readings) but that was it really... This was just after I had the new injectors fitted/filtes and I was made up with the difference, however, I then serviced her and all went to pot (well I can tell anyways) and the 'noise' started, although LPG man says its ok?

When I say 'service' I changed the plugs and leads, see my other posts for the fiasco I had with that and still not right, hence; This is why I may try changing the knock sensor on that bank as one Indie says its that, the other I talk too says it isn't... Although visually the knock sensor looks melted around its outer edges...