Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: mark.adams on 04 May 2011, 08:16:00

Title: What causes a misfire?
Post by: mark.adams on 04 May 2011, 08:16:00

Only happens on LPG, it is a mixer system so fairly simple in operation, doesn't seem to be any pattern to when it occurs, only noticeable on acceleration, feels as though it just skips a heartbeat, VERY occasionally.
Breathers done, new spark plugs, runs fine on petrol.
No EML, no errors stored in ECU.
Have i missed anything??

Title: Re: What causes a misfire?
Post by: TheBoy on 04 May 2011, 08:18:10

LPG needs a stronger spark than petrol, but assuming the HT is OK, you have to look at the LPG mixer system

Title: Re: What causes a misfire?
Post by: Lazydocker on 04 May 2011, 16:58:33

As above really... Could even be the coil pack breaking down :-/ But my first guess (and it is a guess!) is that the mixture is leaning out under acceleration. This is a situation you need to fix ASAP

But, as a word of warning, with a mixer system misfires can be very dangerous and lead to backfires which will do damage to the intake system :o :o

Title: Re: What causes a misfire?
Post by: mark.adams on 04 May 2011, 17:45:20

Thanks guys,
i don't really know where to start with LPG, it's a BRC mixer system, i guess maybe looking for an air/gas leak on the intake is the first place to look...

Title: Re: What causes a misfire?
Post by: Lazydocker on 04 May 2011, 17:48:49

Quote

Thanks guys,
i don't really know where to start with LPG, it's a BRC mixer system, i guess maybe looking for an air/gas leak on the intake is the first place to look...

It would be a start. Not really a suitable system TBH

Title: Re: What causes a misfire?
Post by: TheBoy on 04 May 2011, 17:55:24

I'm guessing (it is a guess) that a mixer to SGI is an easy enough conversion, given tank and pipework to engine is in place?

Title: Re: What causes a misfire?
Post by: Lazydocker on 04 May 2011, 17:56:21

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I'm guessing (it is a guess) that a mixer to SGI is an easy enough conversion, given tank and pipework to engine is in place?

Depends... It's still a complete new Front end kit ;)

Title: Re: What causes a misfire?
Post by: TheBoy on 04 May 2011, 17:57:30

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Quote

I'm guessing (it is a guess) that a mixer to SGI is an easy enough conversion, given tank and pipework to engine is in place?

Depends... It's still a complete new Front end kit ;)

Indeed - but to retrofit is possibly easy, given coolant is (hopefully) in place to evap. Guessing you can't use same evap?

Title: Re: What causes a misfire?
Post by: Lazydocker on 04 May 2011, 17:59:12

Quote

Quote

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I'm guessing (it is a guess) that a mixer to SGI is an easy enough conversion, given tank and pipework to engine is in place?

Depends... It's still a complete new Front end kit ;)

Indeed - but to retrofit is possibly easy, given coolant is (hopefully) in place to evap. Guessing you can't use same evap?

Can't use same vap, and coolant depends how it was plumbed in. Not too bad a job though :y

Title: Re: What causes a misfire?
Post by: TheBoy on 04 May 2011, 18:01:01

Just thinking aloud, given the trouble that mixers are...  ...though my experience is limited purely to tunnie's project shed...

Title: Re: What causes a misfire?
Post by: mark.adams on 04 May 2011, 19:06:22

Well i'm up for it if you guys want to come onboard.
What do i need to buy?
Quick Q? With a SGI, if you turn the car off, the restart, does it start straight away, only with the mixer system, it needs to be turned over for a good 5 seconds before it starts on petrol after being used on gas....

Title: Re: What causes a misfire?
Post by: Lazydocker on 04 May 2011, 19:50:03

Quote

Well i'm up for it if you guys want to come onboard.
What do i need to buy?
Quick Q? With a SGI, if you turn the car off, the restart, does it start straight away, only with the mixer system, it needs to be turned over for a good 5 seconds before it starts on petrol after being used on gas....

It starts on petrol then switches over automatically! Have a look through the maintenance guides for the how to. Kit price somewhere around £250+vat :y