Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Martin_1962 on 08 February 2010, 17:55:08
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Got home and the emmisions light was on
I had some misfire codes - I ignore those - from a few days ago.
I had 0170 and 0173
Can anyone remember what they are for please?
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you should know where the codes are ;)
http://www.omegaowners.com/forum/YaBB.pl?num=1220619696
P0170 Fuel trim malfunction (Bank 1)
P0173 Fuel trim malfunction (Bank 2)
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you should know where the codes are ;)
http://www.omegaowners.com/forum/YaBB.pl?num=1220619696
P0170 Fuel trim malfunction (Bank 1)
P0173 Fuel trim malfunction (Bank 2)
Is this precat :(
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no, maf. same part as 3.2 i believe, search for the bosch part number on the maf it self.
pre cat is 0420 0430. iirc
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no, maf. same part as 3.2 i believe, search for the bosch part number on the maf it self.
pre cat is 0420 0430. iirc
I fitted one last year :o
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no, maf. same part as 3.2 i believe, search for the bosch part number on the maf it self.
pre cat is 0420 0430. iirc
I fitted one last year :o
pattern? or you may have an air leak in inlet or exhaust, its a fuel air inbalance thing.
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no, maf. same part as 3.2 i believe, search for the bosch part number on the maf it self.
pre cat is 0420 0430. iirc
I fitted one last year :o
pattern? or you may have an air leak in inlet or exhaust, its a fuel air inbalance thing.
Pattern
I'll check for inlet leaks - hoses off ect.
Or is it LPG related?
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no, maf. same part as 3.2 i believe, search for the bosch part number on the maf it self.
pre cat is 0420 0430. iirc
I fitted one last year :o
pattern? or you may have an air leak in inlet or exhaust, its a fuel air inbalance thing.
Pattern
I'll check for inlet leaks - hoses off ect.
Or is it LPG related?
KEVIIIIIIIN....?
i'll bet on maf but see what others say.
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Seems to run OK though.
So what is the likelyhood of yet another MAF?
Anyone near me who can lend one for testing?
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I would try it on petrol and see if it still occurs.
Basically, the ECU is having to adjust the fuelling too far to make the mixture correct. It's a problem on both banks, so that rules out Lambda sensors and exhaust leaks.
So - air leak into the intake system, a MAF problem or potentially LPG system in need of calibration / new filters / cleaning out of heavy ends IMHO.
Kevin
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I think the evaporator is on last legs
I wonder though if it is related to the cams and porting?
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I would try it on petrol and see if it still occurs.
Basically, the ECU is having to adjust the fuelling too far to make the mixture correct. It's a problem on both banks, so that rules out Lambda sensors and exhaust leaks.
So - air leak into the intake system, a MAF problem or potentially LPG system in need of calibration / new filters / cleaning out of heavy ends IMHO.
Kevin
Heavy ends?
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I think the evaporator is on last legs
I wonder though if it is related to the cams and porting?
Irrelevant as its a closed loop system.....
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I would try it on petrol and see if it still occurs.
Basically, the ECU is having to adjust the fuelling too far to make the mixture correct. It's a problem on both banks, so that rules out Lambda sensors and exhaust leaks.
So - air leak into the intake system, a MAF problem or potentially LPG system in need of calibration / new filters / cleaning out of heavy ends IMHO.
Kevin
Heavy ends?
Yes Chris, as opposed to the light ends ;D ;D ;D
Heavy ends = Long chain hydrocarbons and moisture in the tank from long term storage at depots and filling stations, basically crud in the bottom of the tank ;) :y
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I would try it on petrol and see if it still occurs.
Basically, the ECU is having to adjust the fuelling too far to make the mixture correct. It's a problem on both banks, so that rules out Lambda sensors and exhaust leaks.
So - air leak into the intake system, a MAF problem or potentially LPG system in need of calibration / new filters / cleaning out of heavy ends IMHO.
Kevin
Heavy ends?
Evaporator cleaned out last year - not too many in there.
No filter
Plastic injectors
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I think the evaporator is on last legs
I wonder though if it is related to the cams and porting?
Irrelevant as its a closed loop system.....
Perhaps the cam changes mean that the car cannot richen the mixture enough?
Car is closed loop, no Lambda connection to the LPG kit.
I will try a day on petrol and see if the emmisions light goes out.
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Consider the system operation.....the ecu measures the air mass going in and adds a quantity of fuel related to this mass......it then checks to see how far out it was by looking at the lambda.
All you do by porting and increasing the cam duration and lift is increase the ability to get measured air in....
So the code you get is because the ecu's calculated the fuel required and the lambda correction values have gone out of range....this is either because the mass of air is being measured wrong or the mixture is weak (would only apply to your lpg setup and only likely to happen near the red line on full throttle)
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The kit I have was borderline enough gas as standard I am wondering if it simply cannot get enough LPG in at higher revs.
I wonder how much for a newer front end?
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So its that dodgy cheepo maf then Martin. If so i believe, possibly wrongly, the bosch item can be had on gay bay for 35 to 55 sobs.
Thanks for info Lee, i'd never urd of em...
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The kit I have was borderline enough gas as standard I am wondering if it simply cannot get enough LPG in at higher revs.
I wonder how much for a newer front end?
It would be open loop at higher levels of load so the engine ECU wouldn't know it was lean.
Is the vapour pressure correct and still where it was when the system was calibrated? If so, and the calibration hasn't changed, there's no LPG problem. The issue would have to be present during conditions of light load to raise these codes.
Kevin
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Current codes are
0302
0306
0170
0173
0130
0300
0300
I understand the 030n ones
So what is a good MAF on say Ebay then?
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Where are the misfire codes coming from? Does it misfire from startup?
Do you have anything that can display live data?
Kevin
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Where are the misfire codes coming from? Does it misfire from startup?
Do you have anything that can display live data?
Kevin
It hiccuped a few days ago going from LPG to petrol - that sometimes sets off a 030n
Unfortunately no live read but a code reader owner works opposite me in the TVR place.
One thing though my test place where a 2.0 scored 25, a 3.0 and 2.6 score 29, tonight the 2.6 on petrol scored 29.6.
These figures are of relative performane
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Errr
I pressed the fuel change button unter full throttle got a short misfire lost a couple of pots so rebooted restarted the car and it ran fine.
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Does it normally stumble when switching fuels? Just wondering if it's having to dial in fuel trim on LPG? Mine is seamless, but it does switch one pot at a time.
Kevin
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Does it normally stumble when switching fuels? Just wondering if it's having to dial in fuel trim on LPG? Mine is seamless, but it does switch one pot at a time.
Kevin
I think it is varying the fuel trim, I never set it up properly, just adjusted it to run right, I didn't think about the injector timing, just that it ran right. I basically used the instant consumption. :-[I concentrated on high RPM where the kit suppliers recommended leaning off.
Since it ran well I left it at that :-[ :-[
However the kit is now over 4 years old, been on this car for 3 years 8 months, the vapouriser has been striped and stuck back together - and I want to replace.
The injectors are all plastic but are known to have a long service life and to be quiet, but do not like high gas pressures.
I really ought to replace the vapouriser and redo the settings for the new cams :-X
As to MAF, I do not know if it is OK or not £120 is a lot on a hunch.
I think I might call AGWW about the vapouriser and ask them how much for a new one.
My boss wiped the software off his laptop >:( >:(.
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Oh stumble - just a little a bit more than it used to but not a lot.
The injectors are said to not reqiure a filter
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Well, I wouldn't replace the vapouriser on a hunch. First thing to try is see if the codes clear when running it on petrol for a while.
When setting up LPG I switch to and from petrol and watch the injector duration on the outputs of the main ECU. This way you can see if the fuel trim is moving. Failing that get a cheap ELM327 cable and watch the fuel trims in the live data.
Sounds like you could do with the LPG tuning software either way - should tell you what your vapour pressure is doing too.
Kevin
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The vapouriser is bodged together and doesn't shut off on the overrun anymore - worn valve lever, so it is a candidate.
Looks like a trip with a laptop is necessary - I'll try to pinch my bosses again.
What is your feeling on the MAF?
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First I've heard of a vap. shutting off on the overrun on a SGI system? It should just maintain a constant vapour pressure relative to the manifold. The injectors don't get triggered on the overrun anyway. It's built into the petrol ECU.
If it's the MAF you would have the same problem on petrol. :y
Kevin
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Lead and CD are in the seat pocket!
The vapouriser damage
(http://i91.photobucket.com/albums/k286/martinimber/LPG/DSC03034.jpg)
A job for a valve compressor
(http://i91.photobucket.com/albums/k286/martinimber/LPG/DSC03042.jpg)
Another view
(http://i91.photobucket.com/albums/k286/martinimber/LPG/DSC03037.jpg)
Found my original save - John wiped my latest one :( :( off his lap top
(http://i91.photobucket.com/albums/k286/martinimber/LPG/lpg1.jpg)
Have you seen this before?
(http://i91.photobucket.com/albums/k286/martinimber/LPG/lpg2.jpg)
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First I've heard of a vap. shutting off on the overrun on a SGI system? It should just maintain a constant vapour pressure relative to the manifold. The injectors don't get triggered on the overrun anyway. It's built into the petrol ECU.
If it's the MAF you would have the same problem on petrol. :y
Kevin
Not shut off completely but a lot, the manifold vacuum adjusts that lever, but the seat damage means it doesn't seal as much as it should.
Runs not bad on gas (smooth ect just not full RPM anymore) well on DECENT petrol.
What would a faulty MAF actually do to the cars running?
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Since then now changes on acceleration and the trims were all 0 I had to richen a couple at low RPM and weaken at higher RPM.
Actually that is not a good example
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What would a faulty MAF actually do to the cars running?
It's the primary input to the ECU for engine load so potentially quite a lot. They seem to fail by gradually losing sensitivity, which gets trimmed out by the ECU until it runs out of fuel trim. Then it'll start to run poorly. Have seen a 2.6 spitting back into the plenum because it's idling very lean.
Kevin
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That sounds a bit yuck
What do I do next then?
I could spend £200 on bits I don't need (but vapouriser is near end of life), and £30 for a MAF was nice and cheap.
Economy is about usual 90 to 100 miles until light 4 goes out on LPG, actually it was about 10 later but I did do 5 on petrol yesterday to see how it was going.
And the other 5 could be the longer run on Sunday
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This is the cheapest I have found :o
http://cgi.ebay.co.uk/Vauxhall-Airflow-Meter-93171760-BOSCH-0281002184_W0QQitemZ230323466205QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item35a0592fdd
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What do I do next then?
Well, if the vapouriser and MAF are both potentially suspects some more diag is required.
Ideally, get a Tech 2 on it and watch the fuel trims and MAF signal in the live data, on both petrol and LPG, and see what's going on.
Or:
Fire up the LPG software and make sure that the vapour pressure is correct and stable, and that the petrol ECU output duration doesn't change huigely when it switches to gas.
Kevin
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This is the cheapest I have found :o
http://cgi.ebay.co.uk/Vauxhall-Airflow-Meter-93171760-BOSCH-0281002184_W0QQitemZ230323466205QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item35a0592fdd
dont believe thats right, 3.2 and 2.6 are same, but differant to 2.5 and 3.0 afaik???
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If the MAF was going would that have explained the lazy performance last week and the 3.0 performance (on petrol) today?
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This is the cheapest I have found :o
http://cgi.ebay.co.uk/Vauxhall-Airflow-Meter-93171760-BOSCH-0281002184_W0QQitemZ230323466205QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item35a0592fdd
dont believe thats right, 3.2 and 2.6 are same, but differant to 2.5 and 3.0 afaik???
Can you remember the part number?
Found a Bosch non VX for the 2.6 for about 108 now
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Actually when it was sluggish I was woondering about the MAF