Failed emissions on MOT. Car is running lean.

[stephend]

Originally Posted by rippedoffagain

I quite like the idea of steaming the engine. I've heard of this trick before but never plucked up the courage to try it.

I think its a great idea, but I have a couple of reservations.

1. Is there no the risk of cold water meeting hot metal and causing rapid contraction and cracking?

2. Not likely to be a problem if you get the measures right, but water wont compress. This means that if too much gets in the combustion chamber in one go, then there's a risk of damage as the piston comes up and tries to compress something that wont compress. I guess this one is just about making sure you only do tiny amounts of water at a time.

It is a risk. Volvon posted a video of him doing it on his old 240, iirc: try a search on that (probably in the 240 section). But... if your emissions are screwed, you either have a cat fault or an engine fault, and steam cleaning the inside of your engine isn't really addressing the problem...

[Laney760]

Originally Posted by FossilFish

Mine is a 96 and has the plug in the cubby, http://www.volvoforums.org.uk/showthread.php?t=98903

Is there another way bar Volvo specialist equipment or do I have to build it.

^^^^^^ Can somebody answer this question please? ^^^^^^^^^

I assumed that when my Volvo started getting cranky I could get a cheapie independent to read the codes but it's looking like maybe not ^^^^^^. I wouldn't be able to afford Volvo fault finding prices nor am confident about making a diagnostic test box

[rogerthechorister]

AFAIK if you have the not-quite-OBD you have to build you own reader as described on this forum - or maybe another member could do it for you or lend you theirs. Most independents I know of just glaze over when you mention the issue - but come to think of it I MIGHT know someone - a car repairer in Kent - with the toy. Watch this space.

[FossilFish]

Originally Posted by Laney760

^^^^^^ Can somebody answer this question please? ^^^^^^^^^

I assumed that when my Volvo started getting cranky I could get a cheapie independent to read the codes but it's looking like maybe not ^^^^^^. I wouldn't be able to afford Volvo fault finding prices nor am confident about making a diagnostic test box

Your names in blue, and so is mine, VOC has a special tool hire service and if this is not specialist then I will request for them to get it. It might be worth a try as I assume many VOC members have this issue and like me cant /won't build it.

[rippedoffagain]

I've just been having a read up on diagnosing defective lambda sensors. I'm not sure its relevant to this discussion, but it was a bit of an eye opener.

Apparently there are two main ways that they fail, and neither will throw a fault code. First, they just become very slow to react, so the engine spends most its time running rich, knackering the cat and using collossal amounts of petrol. The other way is where they simply don't measure anything at all, but constantly give out a steady voltage that is within the expected range, so the ECU thinks its correct. Only the third type of failure, when it reports way outside of tolerance because of either a bad electrical connection or because its failed completely, only then will the ECU raise a code.

In days gone by, I remember you used to be able to get a proper spectrometer stuck up the exhaust to work out the exact composition of the emissions (ie not just sniffing for one type of gas, but the whole range). Knowledgeable mechanics (not the same as poorly trained fitters like some larger chains sometimes use) could then tell you exactly what was up. I don't know if such places/people are still about, but if you can find someone with an oscilloscope to look at the signal coming from the lambda sensor, that might answer a lot of questions.

[stephend]

Idle mixture CO content: setting value (checking value)
B28E: 2.0% (1.0-3.0%)
B200E, B230E: 1.0% (0.5-2.0%)
B23ET: 1.5% (1.0-2.5%)
B230ET: 1.0% (0.5-2.0%)
B234F: 0.6% (0.2-1.0%)
nb on the last one, the setting value is non-adjustable, and the checking value is described as "with Lambdasond disconnected".

[Source: Haynes manual for 740/760]

So 0.7% is about right for what goes into the cat...

[volvoz2000]

I can read the later 940/960 and 850s faults if needed (including SRS/ABS faults that are not readable with the flashing light method). Based near Reading

[FossilFish]

update my car still has high CO level in emissions, I have done the following since my last post on this thread;

bypassed the Turbo+ so put it back
changed the dizzy and rotor
tested the coil with a known good one
tested the plugs
cleaned out the breather box
changed to fully synthetic oil
opened the Fuel ECU hoping that it might have white water marks from a earlier windscreen leak but the chip board looks clean.

Idle



Fast idle (NOTE: the reading got to 1.00 CO and went back down to .40+)



The symptoms I still have fluctuating idle (150-200 rpm at idle) and a the odd misfire (spikes in CO level in emissions) oil from oil cap very minor but indicates high pressure in the head. I have put it on a fault code reader and it is not getting signal from 'fuel'

Tester advised that lambda is fine so the CAT is fine, is it?

I don't wanna put on a good CAT and risk damaging it if it is rich in fuel.

[Chesh740R]

Does the car have egr??? If it does remove it and blank it off.

Also could be a dying/slow oxygen sensor.

[FossilFish]

Yes its a B230FT and it does have a EGR, I can just cover the hole with a plate (20 and close off manifold with a bolt) and discontent the vac line (4) and join 8 and 9 up.



What are the benefits and won't this increase the emissions on the NOX side?

what size bolt fits over manifold in the pic and how did you make your plate?