vy vr running gas

[jezza351]

hi guys, just wanting to know if there is a way to awitch to gas on a vy v6 without needing an injector simulator?
been told to earth out the efi relay when switched to gas and i will need a injector simulator to run it without logging a fault. maybe an option in the comp i can change or a wire in the loom i can earth to let the comp know its on lpg?
Anyone had much experience with this?
any help much appreciated
Cheers.

[jezza351]

no one knows anything about gas switching on a vy pcm?

[VL400]

No experience with it, but couldnt you just switch the PCM to LPG mode like the factory system does? Might still need some error codes masked though. There is VY wiring diagram that has the LPG wiring connections, would need the entire manual to find out more info on what each wire does though .. https://pcmhacking.net/forums/viewtopic.php?f=32&t=134

And to answer your other question, if you remove injector power to cut injectors when running on LPG then yes you will get a fault code relating to injector feedback voltage being out of range.

[VX L67 Getrag]

Not 100% but pretty sure won't bring up engine check light so long as your fuel trims are still being made within tolerance of factory PCM, there is another soft fault that log's injector fault code 57 but won't bring up eng light!

On the switch the PCM to Factory LPG I don't think it's that easy as it controls the system completely different to other aftermarket systems even if they're made by the same company, sounds weird but Yoda Knows more!

Cheers VX L67 Getrag

[Holden202T]

i was under the impression the switch just disabled the injectors and kept everything else going ?

[VX L67 Getrag]

HELL NO!

it's also changes fuel gauges & millions of other thing's, but Yoda would know more than me!

[yoda69]

VX/VY flash PCM with factory LPG turns off injectors, changes to a different spark table, and also controls the LPG mixture solenoid. The old style lpg control computer is not required with this system.
Factory set up only uses the old funigation type system with rich bias mixer and not the current lean bias fumigation system.

If you are running an aftermarket system with the standalone lpg control computer will need the simulator.

If you are running a vapour injection LPG system you will need the simulator, as otherwise there wil be no signal to the petrol injectors to copy.

yoda69

[stevedarman]

Holden can activate the gas with there scan tool
Does anyone know how to turn the gas system on ?

[yoda69]

Holden reflash the VX/Y ECU with their scantool with a LPG tune.
Once wired up as per factory there is a 12V in line to the ECU telling it gas is fitted and the momentary LPG switch is used to change between LPG & petrol.
A flag is set in RAM to enable the vehicle to restart on whichever fuel is was turned off running, exception is a calibration used for fleet which default started to LPG.

I'm reasonably familiar with this system as a I have a VY factory LPG setup, along with a VT factory LPG setup. The VT is much more basic.

yoda69

[Nathen]

I'm reasonably familiar with this system as a I have a VY factory LPG setup, along with a VT factory LPG setup. The VT is much more basic.

yoda69[/quote]

Yoda I have bee trawling throguh the forum and have a couple of Q's
Do you have a XDF for the factory Lpg, I have found some but the don't seem to have some of the things i was expecting to see
How does the Pcm control the gas mixture and does it use the O2 sensors for feed back, and what tables does it use.
The spark is easy as there are 2 Spark maps Hi and low octane, Out I was expecting to see a option to kill the fuel and spark below 300 rpm, as I was led to believe the Pcm does this to prevent backfire.
At the moment I am getting all my information together before I delve into playing with my PCM