Omega Owners Forum

Please login or register.

Login with username, password and session length
Advanced search  

News:

Welcome to OOF

Pages: 1 2 3 [4] 5 6 7 8 9 10 11 12   Go Down

Author Topic: Major misfire on idle, 2.2 petrol manual  (Read 26473 times)

0 Members and 1 Guest are viewing this topic.

terry paget

  • Omega Baron
  • *****
  • Offline Offline
  • Gender: Male
  • Midsomer Norton Somerset
  • Posts: 4633
    • 3 Astras 2 Vectra
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #45 on: 10 April 2018, 22:49:09 »

So, was it a split in the old inlet?
Don't know. I looked for one and could not see one. The MAF sensor was a genuine Vx recent purchase from a  member presumed good, whereas the earlier MAFs were aftermarket and suspect. I suppose I should investigate further.  I was quite prepared to find the coil pack dodgy, or my cam cover gasket repair failing, or my new plugs (Densa) faulty or incorrectly gapped. I was warned the cracked exhaust manifold could cause faulty running. I never expected the induction tract change to cure the fault.
Logged

terry paget

  • Omega Baron
  • *****
  • Offline Offline
  • Gender: Male
  • Midsomer Norton Somerset
  • Posts: 4633
    • 3 Astras 2 Vectra
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #46 on: 11 April 2018, 09:51:43 »

Well done, Terry.
What's an induction tract?
[/url]
Logged

Andy A

  • Omega Knight
  • *****
  • Offline Offline
  • Gender: Male
  • Bristol UK
  • Posts: 1101
    • Omega 2.2i CD manual 2003
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #47 on: 11 April 2018, 09:55:47 »

Well done, Terry.
What's an induction tract?
The assembly of hoses and mass air flow meter that connects the air cleaner to the throttle box. Fitting involves 2 hose clips and one electrical connector.

Terry do you have the part number or size of the two hose clamps that connect the air flow meter?

Mine are knackered.

Glad you got it all sorted. :y

Thanks

Andy
S3 size 40
29-76 USA
one is labelled,
the other says NORMA 72-80
make of that what you will
The diameter of the clamp point seems to about 76mm
Correction: those are the hose clips either side of the air flow meter, not the ones I touched. The air cleaner end clip is labelled 82-92 NORMA, the throttle body end clip is labelled Norma 66-75.

Thanks Terry for the info.  :y
Logged

terry paget

  • Omega Baron
  • *****
  • Offline Offline
  • Gender: Male
  • Midsomer Norton Somerset
  • Posts: 4633
    • 3 Astras 2 Vectra
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #48 on: 18 April 2018, 10:26:47 »

Oh dear. Having repaired the cills, and sorted the stalling, I hoped this car was ready for MOT. In a short test spin, however, the EML came on. I plugged in my diagnoser, up came P0170 lean exhaust. I checked live data, and found the O2 loop was open, even with a hot engine. Both lambda sensors recorded lean, and were not switching rich-lean as they should if the O2 loop was closed.

As this thread testifies, I have changed the first lambda sensor, and the MAF sensor. Members may tell me the cracked exhaust manifold will affect matters, but I have suffered cracked exhaust manifolds before on 4 cylinder Omegas, and they have not affected emissions or brought on EMLs. Atempting to change the manifold, if I can get one, will open a whole new can of worms, so I don't want to go there.

Please advise.
Logged

dave the builder

  • Omega Lord
  • *****
  • Offline Offline
  • Gender: Male
  • Derbyshire
  • Posts: 7760
    • omega b2 2.6 cdxi
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #49 on: 18 April 2018, 10:36:28 »

How big IS the crack in the manifold ?
you could try gum gum or JBweld ,
won't last as a fix but may last long enough to prove one way or another if the crack is an issue  ;)
Logged

terry paget

  • Omega Baron
  • *****
  • Offline Offline
  • Gender: Male
  • Midsomer Norton Somerset
  • Posts: 4633
    • 3 Astras 2 Vectra
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #50 on: 18 April 2018, 11:00:30 »


Good thinking.
I have a MIG welder. I was wondering if grinding a slot into the crack, and then trying to weld a repair into it, might achieve a similar temporary result. Silly idea?
Logged

Bigron

  • Omega Baron
  • *****
  • Offline Offline
  • Gender: Male
  • Witham, Essex
  • Posts: 4808
    • Omega 2.6 V6 Auto '51 Reg
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #51 on: 18 April 2018, 11:21:12 »

I'm not a welder so please don't shoot me if I'm wrong, but my understanding is that welding cast iron doesn't work: brazing does?

Ron.
Logged

Migv6 le Frog Fan

  • Omega Queen
  • *****
  • Offline Offline
  • Gender: Male
  • Webs End.
  • Posts: 11732
  • Nicole's Papa
    • 3.2 Elite. Boxster. C1.
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #52 on: 18 April 2018, 11:33:36 »

Cast iron can be welded Ron.  :y
Logged
Women are like an AR35. lovely things, but nobody really understands how they work.

Bigron

  • Omega Baron
  • *****
  • Offline Offline
  • Gender: Male
  • Witham, Essex
  • Posts: 4808
    • Omega 2.6 V6 Auto '51 Reg
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #53 on: 18 April 2018, 11:45:05 »

OK, lead me to the firing squad, Albs!  :'(

Ron.
Logged

mandula

  • Junior Member
  • **
  • Offline Offline
  • Gender: Male
  • Finland
  • Posts: 174
    • Opel Omega -03, Z22XE man
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #54 on: 18 April 2018, 11:50:20 »

I've read that some have successfully welded those manifolds in-place.

Before welding drive/rev engine hot as possible so exhaust manifold is very hot, disconnect battery and then quickly weld with applicable welding method and then wrap the whole manifold with rock wool and let cool over night. This should prevent repaired manifold to crack/bend.
« Last Edit: 18 April 2018, 11:51:54 by mandula »
Logged

Nick W

  • Omega Queen
  • *****
  • Offline Offline
  • Gender: Male
  • Chatham, Kent
  • Posts: 10833
  • Rover Metro 1.8VVC
    • 3.0l Elite estate
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #55 on: 18 April 2018, 14:31:48 »

I'm not a welder so please don't shoot me if I'm wrong, but my understanding is that welding cast iron doesn't work: brazing does?

Ron.


welding cast iron is possible, but it's a specialist job that's rarely durable on a long thin part like an exhaust manifold. Brazing tends to be a bit more successful, but the heat cycles of a manifold don't help.


Add the cost of doing it(you're not going to do it with a MIG welder for instance) and buying a new manifold is the only viable fix.
Logged

Bigron

  • Omega Baron
  • *****
  • Offline Offline
  • Gender: Male
  • Witham, Essex
  • Posts: 4808
    • Omega 2.6 V6 Auto '51 Reg
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #56 on: 18 April 2018, 14:40:20 »

Yes Nick, that's roughly the way I remember hearing it (I think from Webby the bear - where is he these days?), that welding is at best temporary if it works at all and brazing is the only answer and even that will not last forever.
Would ceramic coating work?

Ron.
Logged

terry paget

  • Omega Baron
  • *****
  • Offline Offline
  • Gender: Male
  • Midsomer Norton Somerset
  • Posts: 4633
    • 3 Astras 2 Vectra
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #57 on: 18 April 2018, 16:48:43 »

Thanks for all the advice, chaps. Could there be any other reason for the O2 loop remaining open? This car, and several other 4 cylinder Omegas I have owned, all had cracks in the exhaust manifolds, but passed MOT emissions tests. Repairing this car looks liable to exceed its value.
Now you see why I hate 4 cylinder Omegas.
Logged

TheBoy

  • Administrator
  • *****
  • Offline Offline
  • Gender: Male
  • Brackley, Northants
  • Posts: 105837
  • I Like Lockdown
    • Whatever Starts
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #58 on: 18 April 2018, 19:31:12 »

If enough air is getting it, it will bugger up the readings, and also upset the fuelling.
Logged
Grumpy old man

terry paget

  • Omega Baron
  • *****
  • Offline Offline
  • Gender: Male
  • Midsomer Norton Somerset
  • Posts: 4633
    • 3 Astras 2 Vectra
    • View Profile
Re: Major misfire on idle, 2.2 petrol manual
« Reply #59 on: 24 April 2018, 16:23:52 »

MOT failed. High lambda, never below 1.15, and 14 advisories. Oh dear.
Logged
Pages: 1 2 3 [4] 5 6 7 8 9 10 11 12   Go Up
 

Page created in 0.028 seconds with 19 queries.