Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Hannah Judes Dad on 28 April 2011, 23:02:22

Title: Vacuum delay unit - emission failure
Post by: Hannah Judes Dad on 28 April 2011, 23:02:22
Just been for MOT and only failed on emissions. I remembered that I have a faulty vacuum delay unit and was curious to know if this were to be fixed it would alter the emission level from the car by much.I have got a replacement cat to fit as well before anybody suggests that I do that.
Title: Re: Vacuum delay unit - emission failure
Post by: freecall666 on 28 April 2011, 23:55:59
what was the reading from mot???
Title: Re: Vacuum delay unit - emission failure
Post by: Hannah Judes Dad on 29 April 2011, 00:03:27
First run Co % .437 Second run .391 (Max .300)
HC first run 52 second run 50 (Max 200) so I passed on that bit :y
Title: Re: Vacuum delay unit - emission failure
Post by: Andy B on 29 April 2011, 00:07:57
Vacuum delay unit  :-/ :-/ :-/ You mean the vacuum reservoirs? They are fitted to hold a reserve of vacuum from when the throttle is wide open ie when the vacuum from the inlet is reduced. I'm willing to be proved wrong but AFAIK they won't have an influence on emissions.
Title: Re: Vacuum delay unit - emission failure
Post by: aaronjb on 29 April 2011, 00:12:33
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Vacuum delay unit  :-/ :-/ :-/ You mean the vacuum reservoirs? They are fitted to hold a reserve of vacuum from when the throttle is wide open ie when the vacuum from the inlet is reduced. I'm willing to be proved wrong but AFAIK they won't have an influence on emissions.

If they were leaking wouldn't that form an unmetered air leak post-MAF? Making the car run lean, which would be learned and corrected for in closed-loop .. if idle is open-loop though that could lead to a rich idle? (I don't know if idle is open- or closed-loop on the Omega, though)
Title: Re: Vacuum delay unit - emission failure
Post by: Andy B on 29 April 2011, 00:27:53
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Quote
Vacuum delay unit  :-/ :-/ :-/ You mean the vacuum reservoirs? They are fitted to hold a reserve of vacuum from when the throttle is wide open ie when the vacuum from the inlet is reduced. I'm willing to be proved wrong but AFAIK they won't have an influence on emissions.

If they were leaking wouldn't that form an unmetered air leak post-MAF? Making the car run lean, which would be learned and corrected for in closed-loop .. if idle is open-loop though that could lead to a rich idle? (I don't know if idle is open- or closed-loop on the Omega, though)

vacuum pipes are tiny. Disconnect one from your car & see if you can tell a difference.  ;)
Title: Re: Vacuum delay unit - emission failure
Post by: TheBoy on 29 April 2011, 11:46:45
Suspect OP means the purge valve ;), though that would be HCs  :-/

As its CO, I'd suspect the cats or the lamdas...
Title: Re: Vacuum delay unit - emission failure
Post by: Hannah Judes Dad on 29 April 2011, 21:14:01
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Suspect OP means the purge valve ;), though that would be HCs  :-/

As its CO, I'd suspect the cats or the lamdas...

I did mean the vacuum delay unit as that is the part I got from Welung,but as you say it sounds like the cats as one of them sounds as if it has collapsed internally  :y
Title: Re: Vacuum delay unit - emission failure
Post by: TheBoy on 29 April 2011, 21:58:24
OK, what is a vacuum delay then?
Title: Re: Vacuum delay unit - emission failure
Post by: feeutfo on 29 April 2011, 22:15:13
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OK, what is a vacuum delay then?
Have been wondering i must say...?
Title: Re: Vacuum delay unit - emission failure
Post by: RobG on 29 April 2011, 22:24:15
Attached to the bagpipes part # 90466214
 (http://i190.photobucket.com/albums/z257/belisensis/vacdelayunit.jpg)
Title: Re: Vacuum delay unit - emission failure
Post by: Andy B on 29 April 2011, 22:26:09
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Attached to the bagpipes part # 90466214
 (http://i190.photobucket.com/albums/z257/belisensis/vacdelayunit.jpg)

opened or closed though isn't it?  :-/
Title: Re: Vacuum delay unit - emission failure
Post by: RobG on 29 April 2011, 22:28:49
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Quote
Attached to the bagpipes part # 90466214
 (http://i190.photobucket.com/albums/z257/belisensis/vacdelayunit.jpg)

opened or closed though isn't it?  :-/
Don`t ask me :D I got a proper engine ;D ;D ;D ;D ;D

I gave you a pic as per my avatar what more do you want ;D ;D ::)
Title: Re: Vacuum delay unit - emission failure
Post by: TheBoy on 29 April 2011, 22:28:54
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Attached to the bagpipes part # 90466214
 (http://i190.photobucket.com/albums/z257/belisensis/vacdelayunit.jpg)
Part of multiram then?

That will have sod all effect on emmissions
Title: Re: Vacuum delay unit - emission failure
Post by: Andy B on 29 April 2011, 22:33:03
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.....
I gave you a pic as per my avatar what more do you want ;D ;D ::)


 ;D ;D ;D I'd not noticed that  ;D ;D ;D ;D
Title: Re: Vacuum delay unit - emission failure
Post by: RobG on 29 April 2011, 22:35:04
Quote
Quote
.....
I gave you a pic as per my avatar what more do you want ;D ;D ::)


 ;D ;D ;D I'd not noticed that  ;D ;D ;D ;D
8-)
Title: Re: Vacuum delay unit - emission failure
Post by: Hannah Judes Dad on 30 April 2011, 23:59:09
Quote
Quote
Attached to the bagpipes part # 90466214
 (http://i190.photobucket.com/albums/z257/belisensis/vacdelayunit.jpg)
Part of multiram then?  :y

That will have sod all effect on emmissions

I didn't know if it would or not but it is worth eliminating anything that may cause a problem.Thanks for the answers folks  ;)
Title: Re: Vacuum delay unit - emission failure
Post by: Hannah Judes Dad on 04 May 2011, 09:22:04
Just to update you all,it was the nearside cat that was causing the problem.I took it off and replaced it with one from my 'spares' car.I decided to open it up and found it was empty!  :o
That might explain the emissions being high  ::)

Good news is I now have another years MOT on the pikey wagon and with no advisories  :y