Question for people running lpg...

[bc1987]

Hi all,
this is a question for people running lpg.
do I have to have different spark plugs for my 4.4i with lpg or will standard ones do?
can I change the lpg fuel filter or will this basically vent all my fuel?
Cheers
b

[LooneyLeon]

Howdy Buddy,

I've had my 2003 4.6is converted to LPG and changed my plugs for Iridium plugs as this was advised by the guy that did my LPG conversion.

I did run it on the normal plugs for a couple of weeks after the conversion and to be fair it seemed fine on those also. It did feel a bit smoother afterwards but then again all cars would as soon as you change all the plugs anyway.

I also have a 330ci which has been LPG converted and I have covered about 20,000 miles also with Iridium plugs.

[kkx5]

Standard are just fine. Mine dosent want to run on iridium, misfiring all the time...

[weirdfish]

The lpg is switched on via a solenoid when the correct, or set temp is reached, so as long as it's the downstream side of the solenoid then you'll be fine to change it.
Would it not be better to get the lpg system serviced by an authorised person, this way they could make sure all is ok.

[davesavage257]

I run LPG on my Saab, and I've just changed over to Iridium plugs when I had the LPG service done before Christmas.  The LPGA fitters agreed that Iridium plugs are much more suitable for LPG, as the combustion temperatures differ, and because of the lower calorific value of the LPG, a stronger spark is beneficial.  I have read on the Saab forums that closing the spark gap slightly may help, especially with misfires.  They come pre set to 1mm, reducing to 0.8mm normally has things running smoother.

[LooneyLeon]

[quote="bc1987"]
can I change the lpg fuel filter or will this basically vent all my fuel?
Cheers
b
[/quote]

Whoops didn't see this question, Ive replaced the LPG filter on my 330 with no problems, just open the case and pop it out, it wont vent any fuel etc, I would wear gloves though as the filter will be covered in what looks like rusty liquid.

[centurion]

I've run several cars with various dose of success and could comment that so long as you do regular/routine maintenance on the engine and LPG system you won't have any issues... in particular, Ger manufactured vehicles work absolutely fine on LPG and I have had nothing but success on several BM's and Audi's in the past with BRC and/or Zavoli systems.

Something to bear in mind is that LPG is based on a mix of propane and butane that could be prone to change in characteristics based on the outside temp which could affect the running of the engine as a result of it (albeit hardly noticeable) hence the comment to use 'better sparks' in my opinion. Plus the fact that LPG has lower octane value {which I guess you were made aware off} you could have that impression that vehicle is not running well, burns more fuel, has on avg. 7-10% more output when on LPG etc etc... suggestion - run it on box std manuf. recommended setup and you'll be just fine .

[tombs]

4 years in I think and the BRC system is running very sweetly....Nearing 100k miles now to. Ive tried both plugs and either seem to make no difference to how the car runs.

[bc1987]

Thanks for all your replies. Gone with bosch iridium quad tips.
haven't risked the filter yet!