Running rough on LPG

[Briles]

Hi Guys
My 4runner has started running a bit rough when it switches to LPG, it's fine on petrol, but as I say, when it switches over, it splutters along. I am sure I remember someone telling me the spark plugs had to be spot on for LPG, can anyone help at all, thanks
Dave.

[jontunstall]

Your spark plugs do need to be spot on, but also not the multi electrode ones. Good old bog standard single spark ones are best.
The best bet is to see if you can get it tuned - they do go out of tune occasionally - mind you are you on injection or induction system?
HTH
Jon

[Briles]

Cheers John, not sure what type of plugs or system are being used currently. If the plugs weren't spot on, may it still run ok on petrol, but not gas ?
Dave

[TonyN]

Check your Vapouriser isn't full of 'heavy ends' its an oily goo that collects over time, you should have a drain plug near the bottom somewhere.

What system are you running, open or closed loop?

[Briles]

Drain plug near the bottom ot the LPG unit Tony ?

[TonyN]

Drain plug near the bottom ot the LPG unit Tony ?

Yeah, the round thing with pipes going in and out.



Check your ignition as been mentioned, LPG needs a good fat spark to ignite, I opened the gaps and advanced the timing alot to get my open loop system running nice on my V8.

[Briles]

Still running like a bag of spanners, changed the plugs - gaps spot on, checked the timing - spot on.

There is no drain plug in the round thing with all the tubes and pipes. Are there any regulators, and should the LPG unit be regularly serviced guys ?

Thanks
Dave.

[Morr]

Still running like a bag of spanners, changed the plugs - gaps spot on, checked the timing - spot on.

There is no drain plug in the round thing with all the tubes and pipes. Are there any regulators, and should the LPG unit be regularly serviced guys ?

Thanks
Dave.

Just a thought, do you run the standard air filter or a performance one?

I previously had LPG in an Opel Vectra fitted with a K&N cone filter, it simply would not idle properly or run right at low revs in the winter months. Warm weather was fine, just the cold and especially the damp affected it. Refitting the original filter box cured all symptoms. Eventually I made a filter box containing an original filter with the K&N ported into the side, and used a solenoid actuated flap assembly to automatically switch the airflow dependant on fuel used and throttle position for use in the winter months, giving me the best of both worlds.

[Briles]

Maurice
Thanks for that, the 4Runner uses the standard air filter setup, I will replace that next and report back. Hope you've pointed me in the right direction m8.
Dave

[TonyN]

If everything seems to be OK, I'd replace the leads, cap and rotor, to be sure its all up to scratch.

LPG will find ignition problems long before it plays up on petrol.

The vaporiser could need servicing, the diaphram will strech over time, you may need to reset the gas mixture, or replace the diaphram. Any valves usually have a small filter in the inlet side.

Do you know what set up you have? Open or closed loop induction, or gas injection?

[rusty]

Take a pic - give us a clue....

Mine is currently running the same way as yours. I will service it soon. I use IRIDIUM plugs. there has been some comments on whether the additional wiring which has been piggybacked to the loom is shielded and does it affect the ignition etc

[MartPigFace]

Lpg

Hi Guys
My 4runner has started running a bit rough when it switches to LPG, it's fine on petrol, but as I say, when it switches over, it splutters along. I am sure I remember someone telling me the spark plugs had to be spot on for LPG, can anyone help at all, thanks
Dave.

Incidentally, what sort of fuel economy are you getting from LPG? I'm debating whether or not to make the change from diesel.

[That Ruddy Squirrel]

Incidentally, what sort of fuel economy are you getting from LPG? I'm debating whether or not to make the change from diesel.

I don't think you can make the switch from Diesel, the 4runners here are petrol, for us diesel guys the best bet is to hit the veg oil


Trev

[Briles]

Problem now fixed, broken power supply, surprised it worked at all really. Thanks for all the great info/advice guys.