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Omega Help Area => Omega General Help => Topic started by: effone on 15 October 2006, 16:32:39

Title: lumpy idle / misfire??
Post by: effone on 15 October 2006, 16:32:39
chaps...

my car is suffering with a lumpy idle... its tick over speed is fine and doesn't move around... but it is lumpy... feels more like a diesel motor than a nice 2.6 v6...

on acceleration the car again seems a bit on the lumpy side... not a really obvious misfire but not as sweet as i thought...

i've cleaned all of the breathers on the engine, and the car has had new plugs, oil, air and fuel filters recently... and i've run some decent injector cleaner through it to no avail...

so...

any ideas...??? i'm scared to mention the word 'coil pack' but could this be it...?? if so any idea what the damage is (bearing in mind in need 2...)

thanks for any help...

ian b
Title: Re: lumpy idle / misfire??
Post by: JasonH on 15 October 2006, 16:52:53
Just out of interest is it lumpy on light throttle, but seems to pull OK under hard acceleration?

If so I think my 2.5 V6 has the same problem. I'm thinking leads or DIS pack but the leads tend to result in a misfire under load.
Title: Re: lumpy idle / misfire??
Post by: JasonH on 15 October 2006, 17:06:39
Hang on yours is a 2.6 that's coil per plug not DIS pack, could be a coil?
Title: Re: lumpy idle / misfire??
Post by: STMO123 on 15 October 2006, 18:07:57
A bit more info might be handy, Ian. What is the mileage on your car? Did it suddenly start doing this or was it a gradual deterioration? Did it happen immediately after you replaced/repaired something?
Title: Re: lumpy idle / misfire??
Post by: effone on 15 October 2006, 18:26:49
seems to be getting slowly worse... hasn't changed due to the replacement of anything...

car has 102k miles on it...

won't be plug leads as it doesn't have any... the coil packs sit directly on top of the plugs...

as i say, the car is lumpy on tickover and through the rev range (on part or full throttle)... maybe not so much at high revs but i don't really rev it all that much (i.e over 4.5k...)

cheers,

ian b
Title: Re: lumpy idle / misfire??
Post by: STMO123 on 15 October 2006, 18:32:39
It seems you've changed/checked most things except coil packs, and they're a bit expensive to be replacing if not needed. perhaps a diagnostic check may be in order but hang fire because the experts will no doubt help you once they recover from their arduous weekend ;D
Title: Re: lumpy idle / misfire??
Post by: effone on 16 October 2006, 09:36:20
any takers...???
Title: Re: lumpy idle / misfire??
Post by: TheBoy on 16 October 2006, 09:48:03
Bearing in mine the fault codes we read off, it may be worth reseating the coil packs.

For the experts, the codes where

Cyl 5 misfire detected (Not Present)
Multiple cylinder misfire detected (Not Present)

Also, see if there is any sign of oil in plug wells, that can causes a mis...
Title: Re: lumpy idle / misfire??
Post by: Marks DTM Calib on 16 October 2006, 09:49:35
The coil per plug units are the favourite.....somebody with tech2 and some test spark plugs could test the modules and identify which one is at fault.

The modules are 93+Vat retail and they are both different......