Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: grennanp on 06 July 2008, 12:10:45

Title: Only firing on 3 plugs
Post by: grennanp on 06 July 2008, 12:10:45
Hi all.
         I'm only firing on 3 plugs ?? I replaced the plugs and my leads are only new - I even used a lead from another plug that I know works and no joy.
Has anyone any idea what could be wrong please?

Cheers
Title: Re: Only firing on 3 plugs
Post by: philhoward on 06 July 2008, 12:31:18
Is it the plug which doesn't work, or the cylinder isn't firing itself?

I'd find it highly unlikely that its the coil pack as two coils are connected together so you'd get 2 or 4.

You need 4 things for successful combustion; air, fuel, compression and a spark in about the right quantities.  A valve problem will knock out either the air or compression; fuel is the injector and the spark will be there if the plug and lead are half decent.

You don't have a load of oil/water in the plug hole, do you?  That will short out the spark quite easily.  I've had both - oil "overspill" when filling up (it was very windy) and remanent water from it raining (only clue was little droplets of water on the plug lead - although there was a tide mark on the plug when i removed it).
Title: Re: Only firing on 3 plugs
Post by: grennanp on 06 July 2008, 12:41:35
No oil or water in the plug well - it's bone dry. I'm not getting a spark.
When I slightly disconnect all leads they will ark but lead 3 won't. I even tried to use the lead 4 which still did'nt work but it works fine on plug 4 - weird...
Title: Re: Only firing on 3 plugs
Post by: Grumpy on 06 July 2008, 19:02:17
Working on the following facts that you've given.
1)Nr. 3 is the only plug not sparking.
2)All leads new and working.
3)All plugs new and working.
4)No spark at Nr 3 using known good plug and lead.

Then it would indicate that there is a fault in the Dis Module
between the coil that supplies plugs 2 and 3, and the output
terminal Nr3.

As the spark is delivered to Nrs 2+3 simultaneously, wasted
spark principle, swap the leads over between spark plugs
2 and 3 at the spark plugs, but leave them connected to their
original connections at the Dis Module.

If the fault is within the Dis Module, the fault will transfer between
spark plugs 2 and 3.
ie. Nr 3 will now spark but Nr 2 won't.

Before replacing the Dis Module, if faulty, examine and clean the Nr 3
output terminal. Ensure there is good contact between the terminal
and the lead.
Title: Re: Only firing on 3 plugs
Post by: Auto Addict on 06 July 2008, 19:41:30
^^^^^^

Sound advice :y
Title: Re: Only firing on 3 plugs
Post by: rickyboy on 07 July 2008, 00:06:05
If it's not the dispack check the injector wiring for splits or breaks.  The wiring is crap on the 2.0 litre.
Title: Re: Only firing on 3 plugs
Post by: JamesV6CDX on 07 July 2008, 01:14:25
Quote
Working on the following facts that you've given.
1)Nr. 3 is the only plug not sparking.
2)All leads new and working.
3)All plugs new and working.
4)No spark at Nr 3 using known good plug and lead.

Then it would indicate that there is a fault in the Dis Module
between the coil that supplies plugs 2 and 3, and the output
terminal Nr3.

As the spark is delivered to Nrs 2+3 simultaneously, wasted
spark principle, swap the leads over between spark plugs
2 and 3 at the spark plugs, but leave them connected to their
original connections at the Dis Module.

If the fault is within the Dis Module, the fault will transfer between
spark plugs 2 and 3.
ie. Nr 3 will now spark but Nr 2 won't.

Before replacing the Dis Module, if faulty, examine and clean the Nr 3
output terminal. Ensure there is good contact between the terminal
and the lead.
 

I agree with Mr Grumpy :y

If you want a spare DIS to try give me a shout :y
Title: Re: Only firing on 3 plugs
Post by: JamesV6CDX on 07 July 2008, 01:16:11
Quote
Quote
Working on the following facts that you've given.
1)Nr. 3 is the only plug not sparking.
2)All leads new and working.
3)All plugs new and working.
4)No spark at Nr 3 using known good plug and lead.

Then it would indicate that there is a fault in the Dis Module
between the coil that supplies plugs 2 and 3, and the output
terminal Nr3.

As the spark is delivered to Nrs 2+3 simultaneously, wasted
spark principle, swap the leads over between spark plugs
2 and 3 at the spark plugs, but leave them connected to their
original connections at the Dis Module.

If the fault is within the Dis Module, the fault will transfer between
spark plugs 2 and 3.
ie. Nr 3 will now spark but Nr 2 won't.

Before replacing the Dis Module, if faulty, examine and clean the Nr 3
output terminal. Ensure there is good contact between the terminal
and the lead.
 

I agree with Mr Grumpy :y

If you want a spare DIS to try give me a shout :y

Although to throw a spanner in the works, (and to quote Mr DTM!!) - you cannot conclude that a new part is functional, and therefore you add new unknowns into the situation!
Title: Re: Only firing on 3 plugs
Post by: grennanp on 10 July 2008, 22:37:43
Cheers everyone. That's sound advice.
I'm working on it at the moment - will let you know how I get on.

Thanks again
Title: Re: Only firing on 3 plugs
Post by: Vamps on 11 July 2008, 01:21:12
I had similar problem, tried everything about to give up and then got a second hand DIS pack off ebay, car running fine now.