hi all

recently had a sprintgas system installed on my el i6. has been reasonably good, economy of around 14-15L/100km without any issues at all.

recently took it back for the free tune-up and since then things haven't been right.

it flat spots or surges on hard acceleration. sometimes high revs high load, sometimes as low as 3000rpm in 1st gear with only half throttle. some times it will flat spot so bad its like i've hit the brakes. other times you can just feel it surging (power coming and going) but it will make it to the redline no worries still. in all cases if you change gear it'll be ok again until it hits higher revs.

but sometimes you can take it to the redline without an issue.

i've taken it back twice now, and they've been reasonably good about it. the first time they said no worries, sounds like tuning, and re-tuned it. but then they told me the problem is still there, your leads are factory 12yo items so replace them. so i did. its still the same. took it back again and they ended up changing the converter and telling me it's OK. its better - but still does it sometimes...

could this problem still be ignition related? the dizzy and cap is only a couple of years old, but i think the coil is factory so it might be worth replacing this. plugs are standard NGK items which i fitted about a month before the LPG conversion.

any ideas or suggestions? i'm considering taking it to another workshop i know of that does sprintgas conversions, but tunes with a dyno, but obviously this will cost me a bit...

the workshop that installed the kit were recommended to me by sprintgas themselves so i'd imagine they have at least half a clue what they are doing.

btw not having any issues with it misfiring under load or any other problems that indicate ignition system issues, on either petrol or gas.

For a start, any tuning for lpg should be done on a dyno. I reckon it could be a fuel flow problem

Most of my LPG Problems come down to Earth leaks - so that the o2 sensor reads wrong.

Make sure you have good earths from Body to Battery, Battery to Block, Block to Body