Okay my vn is running a duel fuel setup but it wont run on petrol and hasn't for a long time and i've been tossing up whether to fix it or go straight gas. I need to know if I can keep my converter and run a gra or impco throttle body and what cost im looking at? Here's the pics the converter, it's an airod wetf that is the converter mounted vertical next to the airbox and the mixer thanks for any help Some original photos have not been recovered yet.

Cant run that convertor for GRA OR Impco mate. You will need a full new underbonnet install if you want to use either of those systems and go straight. I don't think there really is alot of benefit to be had going straight gas, I mean the petrol injectors don't pose a flow restriction to the incomming air, you just need to get a free flowing LPG mixer to get more power and then you can run a dual curve Memcal so you have two seperate tunes, one for gas, one for petrol. If you wan't the ultimate in performance run a Profire ECU and Vapour injection. The Profire ECU will run the coil packs and even dual fuel, but with no mixer on the intake you will have no airflow restriction and you will have the best chance of making good HP. DONT go and get a sequential vapour injection system and use your petrol ECU to drive it. Your injection is group fire and this will never run Vapour injection correctly. You would need to fit a standalone aftermarket ECU like the Profire which is made for vapour injection and then you can run proper sequential injection both LPG and petrol and have infinate tunability. Want to add a massive cam, no problem retuning it. Want to add a pump (supercharger or turbo) just up injector size and retune (in most cases you wont even need to change injectors for gas). The flexibilty it gives you is second to none and it will also control your transmission. Go to the Profire website and have a look around www.profire.com.au (http://www.profire.com.au)

[quote=blownba] I don't think there really is alot of benefit to be had going straight gas, I mean the petrol injectors don't pose a flow restriction to the incomming air, you just need to get a free flowing LPG mixer to get more power and then you can run a dual curve Memcal so you have two seperate tunes, one for gas, one for petrol. Im not keen on the vapour injection cos this is just the work hack and i just want to get it to run better ie; better economy and power. Any ideas on mixers that would work with that converter that flow better? Also the dual curve memcal any more info on that? Thanks

just rip all the under bonnet lpg gear you have off, chuck it on ebay, go and buy yourself an impco 225 mixer, an impco model e converter and electronic lockoff, take it to an lpg place, get them to fit it and leave the dual fuel switch on lpg all the time and you will have a straight lpg car that has nearly no measureable power loss to any other stock petrol vn. would be easily acheivable for under $500 bucks to buy the gear second hand and get it fitted.

Thats the info i was after thanks. I was kinda set on going GRA though Is there a GRA a kit to suit the vn? Or is the impco hands down a better setup? How much would i get for the gear i have? The converter is maybe 5000k's old the mixer i have no idea could be a couple hundred thousand k's old. Some original photos have not been recovered yet.

to be honest mate on a stock car impco wins hands down (and lots of modified cars aswel) an impco setup is very easy to come across, cheap to buy and replace, and is very simple to tune. even if you wanted to do power upgrades later an upgrade to a 425 will feed what ever mods you plan on doing. if a turbo setup is on your plans the previous mentioned setup will get you close to 220rwkw with boost referencing the converter and what not. gra has its benefits for its ease to fit for boosted applications but a gra throttle body wont fit a vn without some sort of adapter etc etc. a simple setup will keep you happy and is easy to upgrade from there if needed.

Thanks man you have been very helpfull. Hopefully my local gas dude will be able to get this stuff for me, not many ppl know what they're on about when it comes to gas round my way

Go see Kurt at Aus LPG conversions in the Gong. I have met him on the liquid injection training and he is a stand up bloke. And very passionate about LPG.

Thanks man will do. There are a few guys down here that touch on gas but only a couple that specialise.

I know this is a little old now... BUT did any one cover about fixing your petrol issue? A common issue with running gas is that people run it to long with out switching to petrol and this dries out engine. If you have not run it on petrol for say a few weeks or so and then stwiched it over and she just stalls or will not start on fuel.. .Chances are the pump has gone. I currently drive a VP V6 running on GAS & Petrol... So by the looks of your Gas, Exact same setup... I would suggest taking the fuel pump out and replacing that, Changing the fuel filter and also service the Fuel injectors. The pump will set you back about $50 if you can get trade price, not sure on retail but can be much more. The rubbers/filters for the jets in total come to about $28 dollars to do a v6... If you need any help or anything, please feel free to yell out. But with the injectors.. .Clean them in petrol and change the filters. Just unbolt the four bolts for the fuel rail and lift the rail then remove each clip for the injectors. they are pretty easy to clean... I did this just weekend gone as i blew an injectors rubber/washer and car was letting in to much air. Just gotta do fuel pump as its shot!

Quote: and this dries out engine. i think you mean dries out the injectors concur with what 6mayhem6 has said. common problem with people who run LPG only in a duel fuel setup -they go to use petrol and it doesn't work...dried out injectors...

That was more than likely the case but 6months ago we had to replace the motor. It was being flooded by the injectors which leads me to believe the tps or the comp itself is shagged. The guy that told my mum what happened to the motor is prob full of it but he reckons it bent push rods or something. The car never ran right on fuel since we got it. So instead of forking out heaps of cash chasing an efi prob we just stuck with the gas as its easier to diagnose and cheaper at the pump. I haven't had time to get round to see Kurt yet but when I get it sorted out I'll let you guys know how it runs after the new gear goes on. As it stands im using 30L of gas to 200kms

15 litres / 100 seems a bit extreme - even for LPG. my old 202 used to do better than that. it may be that your pressure reg has died and is flooding the injectors / pushing fuel past them. i've seen that before on a VN as well...

Fuel reg isn't hooked up and there is no fuel in the tank. Its basically a dedicated gas car at the moment. It seems as though its a regular prob with vn's, I've seen two with the same issue that I know of.

yea injectors, lol. not engine.. well they kinda clog up and you need to soak and clean them properly... Can easily be done so no need to replace them unless they are really shot.... I also did replace the fuel pump and that was gone as suspected... Fuel filter also should be done when the pump is gone as the filter dries up.