From: Marts on 7 May 2010 22:15
> > These will not start on LPG, you have to start on petrol,
> > then switch over.
> Some start on lpg.
It's been 15 years since I owned an LPG vehicle (had two, a VN V6 and an a VR
V8). Both would start on petrol, then over 1,500 rpm switch to gas. But if there
was no fuel I could hold a button in and crank it over to start on gas. If I
rememer correctly, it took some starting, but it'd run.
From: OzOne on 8 May 2010 01:21
On Sat, 08 May 2010 12:15:27 +1000, Marts <marts(a)ymail.com> wrote:
>> 1. LPG start with throttle on most EFI engines can't prevent spark advance
>> "clear flood" mode from advancing the timing far enough to light the air
>> and fuel mixture that's in the inlet manifold, blowing the manifold to bits
>> or backfiring.
>I lost count of the number of shattered airboxes that our Commodores suffered
>because of this.
>In the end I taped the last blown one up and taped a small plastic square over
>one of the holes. So, the next time it blew the plastic bit would fly off,
>acting as a rupture disc.
Aftermarket ECU would be worth a look
OzOne of the three twins
I welcome you to Crackerbox Palace.
From: Clocky on 8 May 2010 05:07
> Athol wrote...
>> 1. LPG start with throttle on most EFI engines can't prevent spark
>> advance "clear flood" mode from advancing the timing far enough to
>> light the air and fuel mixture that's in the inlet manifold, blowing
>> the manifold to bits or backfiring.
> I lost count of the number of shattered airboxes that our Commodores
> suffered because of this.
> In the end I taped the last blown one up and taped a small plastic
> square over one of the holes. So, the next time it blew the plastic
> bit would fly off, acting as a rupture disc.
There are a number of ways and devices to prevent the airbox from exploding
(which is a thing of the past btw)
From: Marts on 9 May 2010 22:09
> > Our Commodes' fuel pumps used to run all the time. Presumably to keep
> > the injection system cool or something like that. Not sure what good
> > it does to the pump if the tank runs dry. I assume that there's some
> > protection to stop them running if it gets that low, but I'm not sure.
> What model Commodore and what system was that?
VN V6, and a VRII 5.0l V8. The system, as far as I'm aware, was a throttle body
type and was connected to the engine computer. Exactly what it did or what model
system it was, I can't remember. We're looking at early 90s gear.
> There is no reason the pump needs to be running all the time.
According to the installer it was to recirculate fuel through the EFI to keep
the injectors cool.