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Omega Help Area => Omega General Help => Topic started by: Webby the Bear on 10 April 2013, 12:43:15

Title: Is this a misfire (quick video)
Post by: Webby the Bear on 10 April 2013, 12:43:15
(http://i1226.photobucket.com/albums/ee402/webbybear1/th_MOV03046_zpsea9934b1.jpg) (http://i1226.photobucket.com/albums/ee402/webbybear1/MOV03046_zpsea9934b1.mp4)

Hi ya,

This is defo coming from the 1,3,5 bank. And I'm thinking one of these cylinders is misfiring and causing that tractor sound and rough idle. What do you think?

I want to do a power balance test i.e. pop the spark plug leads off 1 by 1 and see if the engine changes... where it doesn't I've found the cylinder misfiring. HOWEVER, is it safe to do this ?

 :y :y :y
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 10 April 2013, 14:58:43
right, just googled this stuff... can I wear rubber gloves to do this and that should protect when popping a ht lead out when cars running? not convinced personally
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 10 April 2013, 15:01:13
i'm so stupid. I could just pull the ht lead when its off then turn car on. soooo dumb at times  :-[
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 10 April 2013, 16:09:39
Right allo sorted...... I think . made a quick video of the problem. when HT leads removed the engine changed for the worst on all leads individualy. then I was like ''hmmm whats that hissing noise''......

(http://i1226.photobucket.com/albums/ee402/webbybear1/th_MOV03048_zps7a3fb4df.jpg) (http://i1226.photobucket.com/albums/ee402/webbybear1/MOV03048_zps7a3fb4df.mp4)
Title: Re: Is this a misfire (quick video)
Post by: Kevin Wood on 10 April 2013, 16:12:28
Such a test won't work on a wasted spark setup like the Omega has since pulling one lead actually kills 2 cylinders.

In fact, it's really only relevant to old cars with distributor based ignition. You also have to be very careful about modern ignition systems when they are running. The spark energy is so much stronger that a shock from a deteriorated plug lead can be dangerous. I reckon you could also kill a modern coil pack doing that.

Most modern engines either detect misfires and raise a code to tell you which cylinder it is, or provide a mechanism for you to cut individual cylinders via Tech2 (or equivalent dealer diagnostic interface).

As to the noise, difficult to say from a video but it's certainly missing a few cylinders and not sure what the rattle is. Sounds like air getting in somewhere too. :-\
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 10 April 2013, 16:14:14
Such a test won't work on a wasted spark setup like the Omega has since pulling one lead actually kills 2 cylinders.

In fact, it's really only relevant to old cars with distributor based ignition. You also have to be very careful about modern ignition systems when they are running. The spark energy is so much stronger that a shock from a deteriorated plug lead can be dangerous. I reckon you could also kill a modern coil pack doing that.

Most modern engines either detect misfires and raise a code to tell you which cylinder it is, or provide a mechanism for you to cut individual cylinders via Tech2 (or equivalent dealer diagnostic interface).

As to the noise, difficult to say from a video but it's certainly missing a few cylinders and not sure what the rattle is. Sounds like air getting in somewhere too. :-\

It is Kev, I just posted the vid on it  :)
Title: Re: Is this a misfire (quick video)
Post by: martin42 on 10 April 2013, 18:15:43
have you still got ht leads running under the plenum??
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 10 April 2013, 18:51:39
have you still got ht leads running under the plenum??

put them back mate  :y
Title: Re: Is this a misfire (quick video)
Post by: martin42 on 10 April 2013, 18:56:42
was it running ok when you put coil pack back to original position or happened a while later?
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 10 April 2013, 19:01:22
was it running ok when you put coil pack back to original position or happened a while later?

yeah it was after, martin. was running fine before that. i'm picking up the breather bridge 'o' rings Friday so ill put them on and see if the miss goes. if not then ill recheck all my connections and replace ht leads if I find a fubard one  :y :y :y
Title: Re: Is this a misfire (quick video)
Post by: tunnie on 10 April 2013, 19:04:23
Just goes to show, original place for DIS pack is best  :y
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 10 April 2013, 19:08:15
Just goes to show, original place for DIS pack is best  :y

lol it ran fine in the new position... its now back and runs shite  ::) ;D

Title: Re: Is this a misfire (quick video)
Post by: martin42 on 10 April 2013, 19:12:42
sounds like you might have damaged some of the ht leads then,got any from ralf you can swap them over with
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 10 April 2013, 19:15:08
sounds like you might have damaged some of the ht leads then,got any from ralf you can swap them over with

yes mate. got loads in fact  :y :y :y
Title: Re: Is this a misfire (quick video)
Post by: cem_devecioglu on 10 April 2013, 19:21:22
Webby check the sparks condition.. and there is an obvious air leak..
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 10 April 2013, 19:37:09
Webby check the sparks condition.. and there is an obvious air leak..

the plugs you mean cem?  :)
Title: Re: Is this a misfire (quick video)
Post by: cem_devecioglu on 10 April 2013, 19:41:01
Webby check the sparks condition.. and there is an obvious air leak..

the plugs you mean cem?  :)

yep..
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 10 April 2013, 19:43:12
Webby check the sparks condition.. and there is an obvious air leak..

the plugs you mean cem?  :)

yep..

I've had them out and they look fine mate  :y
Title: Re: Is this a misfire (quick video)
Post by: cem_devecioglu on 10 April 2013, 19:45:03
Webby check the sparks condition.. and there is an obvious air leak..

the plugs you mean cem?  :)

yep..

I've had them out and they look fine mate  :y

some of them must be fouled if there is continous missfire.. and plus dont use the car in that condition, you will cook the cats with unburnt fuel..
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 10 April 2013, 19:45:59
Webby check the sparks condition.. and there is an obvious air leak..

the plugs you mean cem?  :)

yep..

I've had them out and they look fine mate  :y

some of them must be fouled if there is continous missfire.. and plus dont use the car in that condition, you will cook the cats with unburnt fuel..

yep, its on drive not going anywhere for now  :'( ill see what its like when ive sorted the vac leak  :y
Title: Re: Is this a misfire (quick video)
Post by: dbdb on 11 April 2013, 00:02:25
watch that second video again, about 8 seconds in looks to me like a large tear in the o/s rubber intake duct near the bottom.  That would give you a lean mix on that side and inbalance, not sure if it would make that much noise but it wouldn't help.
Title: Re: Is this a misfire (quick video)
Post by: omega3000 on 11 April 2013, 00:28:34
Just goes to show, original place for DIS pack is best  :y

lol it ran fine in the new position... its now back and runs shite  ::) ;D

Pull it back out and check the leads are on the diss pack proper  ;D Not sure if should be making that sound though  :-\ Plenum seals leaking  :-\
Title: Re: Is this a misfire (quick video)
Post by: 05omegav6 on 11 April 2013, 00:30:55
watch that second video again, about 8 seconds in looks to me like a large tear in the o/s rubber intake duct near the bottom.  That would give you a lean mix on that side and inbalance, not sure if it would make that much noise but it wouldn't help.

Just rewatched the second vid. Could be on to summat there :-\

Induction noise is normally quite well contained. Disconnect the pipe between the air filter and the MAF with the engine running and see how noisy it suddenly becomes...
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 11 April 2013, 10:38:57
Thanks guys,

As per the vid i have found one bog vac leak where the breather bridge connects to the throttle body (new o rings ordered).

i'm at work at the mo so cant see the vid. ill rewatch it again asap.

cheers guys, much appreciated
Title: Re: Is this a misfire (quick video)
Post by: omega3000 on 11 April 2013, 12:57:03
Thanks guys,

As per the vid i have found one bog vac leak where the breather bridge connects to the throttle body (new o rings ordered).

i'm at work at the mo so cant see the vid. ill rewatch it again asap.

cheers guys, much appreciated


 :)


Quote
bog vac
  ??? ??? :-\ :-\
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 11 April 2013, 12:57:27
G;day gals, right checked that gash on the bagpipes.... its just a plastic join/seal mark. no gouge  :y :y which im pleased about as i could do without shelling out for a new set  ::) :y

got my new multi meter in the post  8) 8) 8) its a little baby one. so cute. ill post a pic. tested a couple of things. so easy to use as its basic and simple.... like the owner  ::)
Title: Re: Is this a misfire (quick video)
Post by: martin42 on 11 April 2013, 16:42:51
i wonder if you have the ht leads on the wrong way on the coil pack
Title: Re: Is this a misfire (quick video)
Post by: Webby the Bear on 11 April 2013, 17:38:48
i wonder if you have the ht leads on the wrong way on the coil pack

well its defo caused by something. really strange as i'm positive I marked them up correctly. I reckon its more likely to be a HT lead gone TBH as I did swap some round  :y
Title: Re: Is this a misfire (quick video)
Post by: omega3000 on 12 April 2013, 11:21:21
i wonder if you have the ht leads on the wrong way on the coil pack

well its defo caused by something. really strange as i'm positive I marked them up correctly. I reckon its more likely to be a HT lead gone TBH as I did swap some round  :y

Didnt you say you you stretched a lead  :-\