LPG

[hondamake]

Hi Owen. The easy answer is no. The usual strategy with gas is to make the car dual fuel. Start on petrol then when the engine is up to a chosen temperature, which you can preset using your laptop & software, it will switch to gas. Two reasons for this: 1. A fuel enrichment ability in the gas system for cold starts i.e. in place of a choke (mechanical or electronic) is not required. 2. It also gives you the ability to run on either fuel if you can't get access to gas or petrol on a journey, also invaluable in the event of a malfunction in either fuel system. It must also be remembered that you are injecting gas as a saturated vapour, petrol as an uncompressable liquid. At one time Ford developed a dual fuel system which injected liquid gas and was controlled by the main ECU. It was very unpopular and unsuccessful because it required a fuel pump inside the gas tank which was prone to failure due to use of the vehicle with an empty gas tank, when they couldn't find a gas station drivers would run on petrol. If you've ever replaced the pump inside a petrol tank you can imagine the fun to be had replacing one in a gas cylinder!

[hondamake]

On the subject of ECU's one of the BIG advantages with gas is that with the software you can map & remap the fuelling to your heart's content. Connect your laptop to the gas ecu, sit in the passenger seat and get somebody else to drive, and watch the fuelling in real time. Even better if you plug an OBD reader into the cars OBD socket and check your map utilising the fuel trims, don't forget that whilst you know you are running on gas the car doesn't. If the fuel trims are rising or falling dramatically/erratically it is obvious that the engine is trying to cope with a bad map. Even better if you pay for a couple of hours dyno time because then you can check actual power rather than how it feels.

[Dodo Bizar]

Very silly... NOT having full control over the mapping always made me scared of going gas. This was since I had long time full control over the petrol mappings using Crome or eCtune. Well my friend CRX2 does at least have this ability. But reading all this here does make me reconsider. Actually my Civics might stay petrol, but one day I'd like to have something twice the age and twice the number of cylinders. Gas would be a mandatory thing if I'd like to be able to pay for fuel.

[hondamake]

Over the last few years I've owned and driven: S class Mercs, Honda Legends, BMWs, C class Mercs, Cosworth 190 Merc (W201), an LDV truck with a Rover V8 petrol engine, a Merc 308 truck with a 2.3 and auto box. Plus the present cars: CLK (W208), CLK(W209), Mazda 626, Honda EJ6, Astravan. All on gas because I couldn't possibly afford petrol for them, I know I'm lucky because working in the gas biz it comes almost free. My ultimate goal is to build a fast road civic tuned for gas only. I agree with Dodo's thought on keeping his small cars petrol because all the available tuning and performance parts are designed for petrol. For him to change to gas at this point after so much development on petrol would be as traumatic and expensive as divorce and re-marrying. Only with the car you can get a ride anytime you want!

[Dodo Bizar]

Wonderful way with words.

[hondamake]

Thank you for the compliment Joris. But I still think I'm getting the best side of the deal: I'll try to amuse the crowd in return for access to your hard won Honda know-how.

[hondamake]

This is an ebay advert for an injection kit I have fitted to a number of vehicles. It will give you a good idea of the possibilities: 190629414750.

[mynameisowen]

I was just wondering, have you created any LPG cars that are started on LPG?

[hondamake]

Hi Owen. Yes, quite a few. The simpler the system the easier it is. My EJ6 runs LPG only, it can run on petrol at the flick of a switch but doesn't have to. Most gas injection systems can be switched to start on gas but trying it as a permanent strategy can cause problems. If you want to go LPG only then either open or closed loop with a mixer is the best route. You can remove your petrol tank and all the other petrol injection components and install two gas tanks. A large main tank and a smaller reserve tank controlled by switch from the dashboard is the solution to run-outs.

[mynameisowen]

Can you expand on the problems associated with running (especially starting) on LPG? One of the main reasons (aside from the abundance of oil) we dont all run on methanol (or other biofuels) is the problem of starting on pure methonal, in fact my friends final year dissertation is purely on this. Is it possible to start (on cold days) on pure LPG without an issue?