Vt v6 van dual fuel

[Jervies]

Hi every1, been reading up on this stuff for a while now and have finally bought a few things to get me started. Iv purchased a realtime EPROM and cable I still need to get a chip to suit (does anyone have one?) then I plan on running my vt v6 van for dual fuel. I mostly want to just have a play and learn abit, adjust fan cut in temp and firm up shifts for a start then do a dual map to suit gas and petrol. I'm fairly new to all this so go easy on me lol. Can I use a relay to trigger the map changover? Is there a downside to having two maps? Does anyone have any good gas bins for a vt

[charlay86]

What kind of gas system do you have?

[Jervies]

Iv got an impco gas system with a larger inline mixer

[charlay86]

So is it not the factory VT LPG system then?
Is your plan to set the PCM up to think it has the factory setup and use the LPG spark maps etc?
you could look at the factory LPG tunes for an idea of the timing to run, but obviously it won't be optimal for your van.

[Jervies]

Yeah not the factory gas, it's more the timing and ect i want to use so I can get more power and better economy.

[Jervies]

heres a few logs of gas and petrol on the van, i think im going to have to get a wide band so i can see the correct afr.
let me know if theres any things going on in the logs that i should pay attention to

[yoda69]

The VT LPG factory system is easy to replicate when compared with the later VX/VY system.
I'd recommend changing to a factory style setup if possible, as the LPG bin then controls the spark differently for Petrol & LPG and also disables all the BLM's ( so doesn't run like a dog when switching back to petrol), injectors and fuel pump when running on gas. The afternarket LPG computer then controls the mix with the Fuel Control Valve (FCV) only when running on LPG and the ECU takes care of the spark. The only problem that may arise is to do with the Valve Seat Recession code where it adds some petrol under certain conditions, it needs to know that there is petrol in the tank, which I think gets sent to the pcm via the instruments, I would guess if it doesn't see a signal it won't add petrol.
Attached file is how I wired mine up.

yoda69

[Jervies]

I was just going to run the setup I already have and just use something to switch the bins over. Does the standard gas chip already have that built in? I was also thinking I'm running vs injectors on a vt ecu I think I read some were there a different size?

[yoda69]

Dual Bins on a VS/VT style memcal are a little harder, need something like a G6 Adapter from Moates and the rotary switch.
Standard gas chip has dual Spark Maps and disables injectors, BLM's, fuel pump etc when running on gas, but only works if wired up as per factory setup, most aftermarket setups leave the computer thinking it's running on petrol, and then causes havoc with BLM's as it tries to control mixture.

yoda69

[Jervies]

Sorry but what's blm? Lol I'm challenged