LPG Discussion Forum

Hiya guys, recently fitted a kme nevo system to my wifes 1.8 16v zafira. Car runs beautifully on petrol and gas but ive noticed a small niggle and wanted to know if its normal or if i can turn what its doing off?, basicly when the engine is cold and waiting for the vapouriser to get up to temp thr gas injectors start pulsing open and ive confirmed via the software that the gas rail pressure goes all the way down to 0, once up to temp, 40c, the gas valves open pressure hits 1.2bar and car drives normal. But why is it purging all of the gas out of the system to start with? None of my other systems do this.
Cheers, Mark.

It's a while since I last used the Nevo software, but could that be the 'preheat injectors' setting? It pulses the injectors rapidly to get the coils warmed up so that when switchover occurs in very cold weather they're not sluggish. See if that's selected.

Its all sorted now, you are correct rich, the injector heating was enabled, cheers Mark.

It's not really the coils that need heating, coils work better when cold... lower temp = less electrical resistance = more amps = stronger magnetic field - It is the magnetic field which moves the plunger in injectors, it is the plungers that may stick.

Pulsing injectors with reducer solenoid off is novel but unlikely to help much.. Thinking must go along the lines of heating coils, which surround plunger posts, will allow heat to soak to plunger posts... That may help a bit but not much. On the downside, there will (if no leaks) be a volume of pressurised gas in the lines to injectors which could have adverse effect on fuelling for the short time until that volume is used.

If heating were needed it would be better to do it the old-fashioned way with thermostat controlled injector heating mats, better still to fit a type of injectors that aren't affected much by cold gas temps - some types of injector are much more affected in terms of response than others regards temperatures.. There is also the slightly different subject of some injectors being much more likely to see gas re-condense inside them than others.

For most installs with temp stable injectors, KME's 'switch back to petrol for loads above X with reducer temp below Y' feature is much more useful than injector heating.

Has disabling injector warming stopped the zero pressure in morning situation?

Simon

Yes simon it has, i switched off the injector heating, cheers Mark.