LPG Discussion Forum

Hi

New here and hoping to learn more about this LPG system of mine

I have a BMW E46 330ci with a KME system installed (20 months ago) and I've had many issues over the last year which are finally fixed - Car had vacuum, oil & exhaust leaks and a faulty o2 sensor and the LPG needed a new filter and injector.

Now that the leaks are sorted I can see using BMW INPA tool that the LPG is simply all wrong.

When I reset the BMW fuel trim adaptation I have near perfect STFT/LTFT when running petrol but they not so happy when I switch over to LPG. Its reading too rich, eventually adapting the LTFT to compensate and in turn causing issues when switching back to petrol.

I'm guessing that this is due to the LPG being tuned/mapped with the petrol when all these leaks were present and therefore i'm thinking/hoping it just needs a re-map?

I have been looking at the software on KME site and diagnostics leads available through ebay and I think I might just be able to sort this myself.

I'm about 75% sure which PC connector leads I require but would rather be 100% sure before i part with the cash!
Could anyone point me in the right direction, maybe recommend a diagnostics/tuning kit with software?
I'm sure I need the kit with 1x black usb cable and 2x small grey cables (one with small connector and other with large) - would this sound about right?

Also, as i'm a novice, how difficult is KME software to use? Is it possible to ruin the system with a wrong click or are the instructions on the KME site straight forward to follow, my first impression is they look ok?

Cheers
James

If you are looking at cables from WTV, you'll be OK. If you look at their website (http://www.wtv-uk.co.uk) you'll see they do a serial and USB version. You don't need both of the small cables, just one or the other depending on which connector you have on your system. Early ones used the white Molex connector, later ones went over to a 4 way Supaseal connector. Can't help with how easy the software is to use but your diagnosis seems spot on.

i would say your assumptions are pretty much bang on, and no its not really possible to ruin everything with one click other than "delete map" as long as you save the file first. The worst you can do is make it worse and have to reload the old configuration back in.

Thanks ,

I'm going to give this a go, now feeling confidant I will get this fixed..

If it goes well then you have saved me a round trip of 600miles back to the installer

Cheers

Good luck ! Just take your time. All the information is out there.

On the KME systems, if you right click above or below a point on the 'model' map, the multiplier will be dragged to where you clicked on the map... You could seriously bugger up the map by doing this, so do save your map first. Before adjusting the model, clear any 'rpm correction' the installer has dialled in. Is this a Nevo or Diego KME system?

Some funny things happen on certain BMW straight 6 models regarding fuel trims... If you have had a MIL light error and reset it, the fuel trims go back to zero like you'd expect, but then the LTFT's won't move until the ECU has passed all it's IM readiness checks (ok not unique to BMW's). There seem to be different idle trims for different engine temps and some seem to aim for a richer idle mixture until IM readiness is achieved. Best advice after resetting BMW straight 6 codes / trims is to drive around on petrol for a good while, mixed driving, idling, a few restarts, etc, before attempting to calibrate the LPG system.

Simon
Lpgc