Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Julian James on 28 February 2011, 22:47:04
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Welcome to one of the most difficult problems with cars...
Just want to say thanks for everyone who has helped me out so far on here. Invaluable advice and pointers!!
So onto the topic at hand. Failed MOT today on a few things:
n/s/f Headlamp Insecure, and also kickup goes to o/s (like a french car). How did this pass last year?! (dodgey dealer) So I need a n/s Headlight cluster, HID maybe? My headlights don't match at the moment anyway... :-/
Both rear coil springs incomplete. (Was at WIM less than a month ago, shame this wasn't spotted...)
Handbrake stuff and reg plate, but quite straight forward I hope.
And of course EMISSIONS failure being the big one....
CO content is excessive at idle (1.32% [norm is 0.5%]) and at fast idle (~2-4x norm)
HC level is fine at both speeds
Lambda value is fine (this is ratio of CO? to O2 - ?) at both speeds
Recent relevant work so far:
New Coolant Temp Sensor (Today)
Cleaned plenum, throttle, breathers, intake bridge (and what I could of EGR and ICV) (Thursday)
Cleaned MAF - with carb cleaner (Thursday)
New Spark Plugs (Thursday)
New Air filter (Tuesday)
New Fuel Filter (Tuesday)
Injector Cleaner - Redex (Last weekend? and half a tank since)
Other Service items - Oil + filter change etc (Tuesday)
Coolant flush - but prob not adequate (Monday)
Checked injector wiring on fuel rail (Tuesday) [& will post an wiring info if one doesn't exist :)]
Tramp attempt to clean inside cylinders by putting in carb cleaner and turning over (without crank sesor) (Wednesday)
Compression Test - results fine, all around 240-250 (December)
Paperclip Test - no codes stored (Tuesday)
Tried to look around for exhaust leaks from engine but didn't find any.
2-4-6 Lambda sensor wire/connection looks dodgey but haven't looked closer yet.
Also went for long run right before test.
I had a smell of fuel recently, I think it was all the time, but it was right from startup.
Sparks looked like they had been running rich before change. After change and running for the weekend, they had more black that I would have expected in 3 days, so prob still running rich. I then changed Coolant Sensor, and I thought the fuel smell had mostly gone while I was doing my pre MOT run.
All spark plugs looked fairly similar before and after change. So I guess this rules out a single chamber problem. (faulty injector etc) I also guess it's not bank specific...
So that's the situation. Don't really know how to approach fixing it.
Reluctant to just throw money at it, like changing MAF / Lambda / Cats blindly in the hope of fixing it.
I do have a free retest in 10 days (current MOT expired on sunday though). And the guy said I can come back and have emissions checked for free, then book resest for everything else if it's all clear. Nice of him :)
Since there are 2 lambda sensors, do they only tweak mix on their respective bank? ie, if it's global overfuelling, unlikely that both would have failed?
I've read somewhere that you can do a voltage test on lamda sensors? And also a signal response test? (seeing how voltage varies as you blip throttle) Can these tests be done on the Omega? Any one know how exactly??
Also thinking maybe it's best if I try and get some proper diagnosis done??
I feel like emissions is always an abyss of possibilities!!!
So there's my mess.
Hope I've included all info.
Please feel free to make educated suggestions! Could do with some pointers on where to start, or possible tests I could do etc!!
Thanks in advance! You're all amazing!!! :D
Julian
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Secure n/s headlight and adjust levers on back of lights to UK dip - though could be yours may be fitted with non UK lights (probably off ebay!)
Emissions - change MAF - cleaning it likely to have buggad it up. Then Italian tune up on way to MOT - should reduce emissions.
HTH
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I know you have stated that you have used Redex injection cleaner but i had emission problem at a previous MOT and the tested recomended that i used a bottle of Forte injection cleaner. I put some in (£14 to £15 a bottle) and took it for an "Italian tune up" up a couple of junctions of the motorway and it passed ok the next day. Just a thought. ;)
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hard call with the maf expensive part to replace on a whim! but it is certainly a fuelling situation running too rich imo,does it idle normally?
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Yeah, I should have made that clear. By "long run" I meant italian tune up! AKA Drive it like you stole it. Went A roads and couple of junctions of M5 and back, then straight to MOT station. Will do the same again next time!
dbug:
yes probably off ebay lol... the dealer got everything from scrapyards too, so "new coil pack and HT leads" are 2nd hand also. no idea about the levelers and adjusting for UK dip. is there a preset for that?
robbo:
So all you did was Forte and Italian tune up? And it went from fail to pass? Do you know what reading it originally failed on?
Have you guys ever used things like Wynns Clean Burn Emissions Reducer (Pre-MOT)? Do you think it is just the same as injector cleaner, or it makes the fuel burn more efficiently? (oxidising agents etc)
Also can't find Forte in any places around me (quick search). But in that price range, Slick 50 injector cleaner comes highly recommended by mechanic friend. Ever used it?
Would a higher octane fuel be better or worse (Shell Optimax for example)
Is there any way I can test / isolate MAF?
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mrgreen:
I'm with you on that. reluctant to just go hit an miss unless I can confirm MAF is the problem.
It seems to idle fine. Used to be ~1200 before all the service items above, now it's around 700.
Also think I closed the throttle a TINY bit. Also idles fine when I forget to put ICV connector back! lol
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Yeah, I should have made that clear. By "long run" I meant italian tune up! AKA Drive it like you stole it. Went A roads and couple of junctions of M5 and back, then straight to MOT station. Will do the same again next time!
dbug:
yes probably off ebay lol... the dealer got everything from scrapyards too, so "new coil pack and HT leads" are 2nd hand also. no idea about the levelers and adjusting for UK dip. is there a preset for that?
robbo:
So all you did was Forte and Italian tune up? And it went from fail to pass? Do you know what reading it originally failed on?
Have you guys ever used things like Wynns Clean Burn Emissions Reducer (Pre-MOT)? Do you think it is just the same as injector cleaner, or it makes the fuel burn more efficiently? (oxidising agents etc)
Also can't find Forte in any places around me (quick search). But in that price range, Slick 50 injector cleaner comes highly recommended by mechanic friend. Ever used it?
Would a higher octane fuel be better or worse (Shell Optimax for example)
Is there any way I can test / isolate MAF?
well when i was having problems with my volvo i always suspected MAF and if you look on youtube there is certainly ways to test them but i'm no rocket scientest so i never did!! looked well out of my league! but by unplugging it it should make a difference to the way it's running and i must admit thinking back the volvo's problem was definately this as when i unplugged it it made no diffference but i'm sure someone will be along to clarify how you should go about this more professionally!!
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mrgreen:
I'm with you on that. reluctant to just go hit an miss unless I can confirm MAF is the problem.
It seems to idle fine. Used to be ~1200 before all the service items above, now it's around 700.
Also think I closed the throttle a TINY bit. Also idles fine when I forget to put ICV connector back! lol
Get someone with a code reader or Tech 2 to plug in.
If your O2 sensors aint working properly this can cause high emisions eg
I had a 4.6 Range Rover that I took for MOT which failed miserably on emissions in fact off the scale ;D both O2 sensors had packed in which I found by putting my multi meter into the wires on the ECU, which was thinking the car was running lean... so it was saying "Throw some fuel in, Throw some fuel in!" that much so it was down to 8mpg now the Range Rovers will do that and not put on the EML.... usually Omegas do but worth checkingin my opinion :y
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Cant remember precicely the readings but i know they were just over and a fail. Yep, that`s all i did. Put a bottle of Forte in and did "tune up". :y
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well omega parts are definately cheaper than volvo i found this which i would give a heads up to for that money anyway!!
http://cgi.ebay.co.uk/VECTRA-B-OMEGA-2-5-3-0-V6-AIR-FLOW-METER-MAF-95-02-/120683646545?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item1c194e4e51
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Mine were about 3x the limit, so perhaps not "just over" lol. but it's defo worth doing that with a more serious additive! thanks!
So for the tests:
MAF - Unplug. If no change, then it wasn't working in the first place.
(Although I though this was the main way the injector timing worked so running at all would be hard if this was out of action - correct me if I'm wrong!) Also, am googleing in the mean time.
Lambda - Multimeter. Where exactly am I sticking these on the omega? And what reading am I looking for? Thank you Lord Vadar :D
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mrgreen:
I'm with you on that. reluctant to just go hit an miss unless I can confirm MAF is the problem.
It seems to idle fine. Used to be ~1200 before all the service items above, now it's around 700.
Also think I closed the throttle a TINY bit. Also idles fine when I forget to put ICV connector back! lol
Get someone with a code reader or Tech 2 to plug in.
If your O2 sensors aint working properly this can cause high emisions eg
I had a 4.6 Range Rover that I took for MOT which failed miserably on emissions in fact off the scale ;D both O2 sensors had packed in which I found by putting my multi meter into the wires on the ECU, which was thinking the car was running lean... so it was saying "Throw some fuel in, Throw some fuel in!" that much so it was down to 8mpg now the Range Rovers will do that and not put on the EML.... usually Omegas do but worth checkingin my opinion :y
i would say that's damned fine advice!!
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Mine were about 3x the limit, so perhaps not "just over" lol. but it's defo worth doing that with a more serious additive! thanks!
So for the tests:
MAF - Unplug. If no change, then it wasn't working in the first place.
(Although I though this was the main way the injector timing worked so running at all would be hard if this was out of action - correct me if I'm wrong!) Also, am googleing in the mean time.
Lambda - Multimeter. Where exactly am I sticking these on the omega? And what reading am I looking for? Thank you Lord Vadar :D
I have never used my Multi meter in the ECU on an Omega mate only the Range Rovers. I would get someone with a tech 2 or a decent code reader to have a look at the live data of the O2 sensors etc :y
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ok cool. tech 2 is ideal way to go then.
as I'm fairly new to the scene I don't really know who has one. I'm guessing Lee prob does? as he has 12 omegas in his posession. :P
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Your more than welcome to pop it up here and lets have a look :y
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ok cool. tech 2 is ideal way to go then.
as I'm fairly new to the scene I don't really know who has one. I'm guessing Lee prob does? as he has 12 omegas in his posession. :P
Not sure if Lee has a Tech 2 but sure he has a good enough code reader :y
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that would be awesome mate! thanks. depends when you can do of course. pm?
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Hope daz sorted you out today.
Speak soon
Pete