Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: SPeters on 06 March 2008, 12:18:11

Title: LPG converted - Running poorly
Post by: SPeters on 06 March 2008, 12:18:11
Hi all, great meega site, by the way  :y

I have a 2.5 CDX with an LPG conversion, which was fitted approx 18 months ago now. It is the Romano multipoint system (which i was told is supposed to be the best for omega's ??)
Anyway, i have a problem with it, apart from the time it takes to kick in which i suppose could be down to the thermostat (being replaced at the weekend), when on gas the car seems to mis-fire on one plug at least. It runs in a very lumpy manner, power is down for quite a while and it seems to be using more gas than it should.
The weather seems to make a slight difference to how it actually runs, nice weather = runs a bit better than in cold or damp weather.
It got so bad in the latter half of last year that i stopped putting gas into the car and just used it on petrol, but our wonderful government (/sarcasm) have seen fit to keep attacking the motorist with ever higher fuel prices.

Any suggestions to cause or repair are welcome.
Title: Re: LPG converted - Running poorly
Post by: Martin_1962 on 06 March 2008, 12:21:11
Have you replaced your plugs recently?

They do wear a lot quicker than on petrol alone.

Use single or twin electrodes rather than quad.

Also try dropping your changeover temperature and time delay, I dropped mine to low 20s and the shortest time available.

Title: Re: LPG converted - Running poorly
Post by: SPeters on 06 March 2008, 12:25:52
The only problem there is, the whole thing was setup using a computer (laptop). How would i change the temp / time without one or what software / hardware would i need
Title: Re: LPG converted - Running poorly
Post by: Martin_1962 on 06 March 2008, 12:27:12
Leads are about £40, software is on the importers web site.

Get those plugs done first
Title: Re: LPG converted - Running poorly
Post by: JamesV6CDX on 06 March 2008, 14:07:55
when the engine is hot, put your hand on the evaporator and make sure it's red hot

If it's not I suspect it's not been plumbed in properly.

The evaporator should always have it's feed from the coolant bridge, and then back to the HBV...

T peices do not work properly!

Title: Re: LPG converted - Running poorly
Post by: Martin_1962 on 06 March 2008, 16:23:12
Quote
when the engine is hot, put your hand on the evaporator and make sure it's red hot

If it's not I suspect it's not been plumbed in properly.

The evaporator should always have it's feed from the coolant bridge, and then back to the HBV...

T peices do not work properly!


Mine has Ts mine works fine
Title: Re: LPG converted - Running poorly
Post by: The Cambelt Kid on 06 March 2008, 22:47:32
Quote
Have you replaced your plugs recently?

They do wear a lot quicker than on petrol alone.

Use single or twin electrodes rather than quad.

Also try dropping your changeover temperature and time delay, I dropped mine to low 20s and the shortest time available.



That's just reminded me to do mine.  Are the quad ones really that bad for LPG?  i'm guessing x2 strong sparks is better than x4 slightly weaker ones?
Title: Re: LPG converted - Running poorly
Post by: The Cambelt Kid on 06 March 2008, 22:48:56
Is your coolant level ok?
Title: Re: LPG converted - Running poorly
Post by: SPeters on 06 March 2008, 23:36:54
Quick update before bed time.
Spent 4 hours on the car today and may have discovered the problem.
It would seem that i have an oil leak !! Both of the 2 front spark plugs on the passenger side are swimming in the stuff so i am guessing that the rear one is also (though i couldn't get at it today).
So now i've got to clean the breather system, replace the cam cover gaskets, replace plugs and leads and hope for the best.
Does anyone have a Trade Card with Elasoplast??
Title: Re: LPG converted - Running poorly
Post by: Taxi_Driver on 07 March 2008, 09:42:20
Quote
Quote
Have you replaced your plugs recently?

They do wear a lot quicker than on petrol alone.

Use single or twin electrodes rather than quad.

Also try dropping your changeover temperature and time delay, I dropped mine to low 20s and the shortest time available.



That's just reminded me to do mine.  Are the quad ones really that bad for LPG?  i'm guessing x2 strong sparks is better than x4 slightly weaker ones?

You dont get 4 sparks with quad plugs or 2 sparks with dual plugs......only a single spark  :y
The idea is the plugs last longer......the single spark jumps between the path of least resistance so evenly wears away the earthing points.

However its been suggested by MDTM that the quad plugs shield the spark too much......and dual ones are better.

iirc vx recommend change for quad plugs is 80k miles.....40k for dual plugs.....but 1/2 that for dual fuel cars.

I use dual plugs.......and tried to get 20k outa a set of plugs once......ok i did but getting towards 20k.....my omega was missing more than normal on lpg.....so i went back to 10k changes  :y