[BLUE MQ]

Have a 1990 GQ LWB, TB-42 carby, auto, going straight LPG, just taken petrol tank and lines out.
What I need to know, is it better to use an EFI intake and throttle body or use the oridginal manifold and put straight LPG throttle body on? Already have twin gas tanks, total of 180lt of useable gas. So any advise would be great. Carby ran great even on petrol. Will be selling everything to do with the petrol system once conversion is done.
With thanks Jeff.

 

[CrazyTrolling]

hey man where did u fit your tanks??

 

[UR-50-LO]

EFI intake manifold would be better for all round performance but you will never find any restriction in the original intake, especially in naturally aspirated form. Even with a moderate turbo conversion it will be fine. IMO unless you can get an EFI intake on the cheap I would just go the GRA adaptor plate & throttlebody on the original manifold. You can always have them power ported later on if really needed (say if you upgrade to a decent turbo set-up)...

 

[Ste]

why straight gas?i would go duel fuel, if your gas converter packs up when your bush you can always flick over to petrol.Its always good to have a plan B

 

[BLUE MQ]

Thanks for the replies, CrazyGQ, have 100lt(usable) tank mounted under back and 80lt(useable) mounted in behind middle row seats, lost a bit of cargo area but I dont carry alot around. Then have cargo barrier mounted between seats and tank, and a shelf over tank, for dog to sit on.

UR-50-LO, yes as you have said the EFI manifolds are getting hard to find, and are really exspensive to buy, so I think I will just try using standard manifold with gas throttle body on it, would like to one day maybe put on turbo, but cant see it happening due to the cost.

Ste, gone straight LPG as running duel fuel can be a pain also, recently had petrol pump do the diaphram, only found this out when stopped and had oil under car everywhere, it had pumped oil into fuel tank. Had to put almost 6lt of oil back in. other reason for going straight LPG is you can get more power and better economy from running straight LPG compared to duel fuel. I have a spare converter that if we are going anywhere that is off the beaten track that I pack in tool box with a few other spares, spare converter has been rebuilt, all fittings taped up so that no dirt, dust or water can comtaminate it. It only takes about 5-10 minutes to change a converter if needed, wouldnt be any different if had a petrol pump stuffed up when out bush, if only running petrol. Any other problems to do with LPG, eg;safety switch, wiring or switches can all be quickly by-passed to get you going, and get problem fixed when get home or back to civilisation. Sorry to ramble on, but I am sure that I am not the only 4wder that is running straight LPG. Thanks again for all the replies.

 

[CrazyTrolling]

Blue MQ keep us posted on the results on the straight gas conversion im thinking of doing the same
i only get 320kms to 95l of gas atm tho :/

 

[alper5005]

Blue MQ keep us posted on the results on the straight gas conversion im thinking of doing the same
i only get 320kms to 95l of gas atm tho :/

I get about 170 kms to 40 lts of LPG. Now converting to semi sequential LPG injection with the carb on for petrol. Hope to get better power and 18-19lts of LPG per 100 kms.

 

[waynesworld]

well i had a v8 falcon ute for a long time and all i did was basically gut the carby so all that was left was the housing and a butterfly left and it worked great cause fuel consumption was all related to my right foot it still now is very economical if you want it to be or you can use the tank in bugger all if ya need to go and simple never had a problem dont let the gas people talk your wallet out of your pocket

 

[STOOL]

I have the same set up as above and its very simple` reliable AND CHEEP

Holley base plate with butterflys `
Than a Impco gas carb on top.