MOT Fail - Emmision

[swfsnapper]

Hi,

First off I'd like to say this is my first post, Second, I have to admit I don't have a Galaxy but an 1996 2.0i Alhambra... I hope that doesn't prejudice me?

I'm very much a DIY mechanic and enjoy working on my car, but unfortunately the last MOT the car failed on emissions and I'm stumped as where to go next.

Initially the cars results were...

Fast Idle Test
CO 0.3% Pass
HC 25 PPM Pass
Lambda 1.19 Fail (Limit 0.97 - 1.03)

Second Fast Idle Test

CO 0.0% Pass
HC 8 PPM Pass
Lambda 1.17 Fail (Limit 0.97 - 1.03)

Natural Idle test
CO 0.00% Pass

Not a problem there, the MOT tester pointed a large leak in the brake vacuum hose saying it could! possibly be the reason why the Lambda was reading high?

Pipe replaced, air filter replaced, feeling good about a pass put some Wynes engine cleaner in high octain (99) petrol, Italian tune up and made sure engine was hot before the retest...

FAIL......


Fast Idle Test
CO 3.13% Fail (Limit <=0.3%)
HC 103 PPM Pass
Lambda 0.92 Fail (Limit 0.97 - 1.03)

Second Fast Idle Test
CO 4.77% Fail (Limit <=0.3%)
HC 125 PPM Pass
Lambda 0.87 Fail (Limit 0.97 - 1.03)

Natural Idle test
CO 10.12% Fail (Limit <=0.5%)

Opps... Tester said, I don't know what you've done under the bonnet, and I'm not sure which way to go??? So now I'm stumped and regretting the Wynes engine cleaner and Italian tune up. Although at this point I'd like to note the car is running better then it ever did (High octain fuel?)

On investigation I found a feed pipe off the vacuum hose - going to the fuel rail pressure regulator - blocked!!! It looks like I may have disturbed it, dropped down on the the block and melted shut? New better pipe fitted and all other vacuum off take hoses replaced. At this point a new O2 sensor had tuned up on the door and for the heck of it I replaced that.

The tester guy said he would only charge me for a quick emission test at this point, very nice of him, although I was insulted because he obviously didn't have faith in my fault finding skills and he was right.....

Third emission test.... Fail


Fast Idle Test
CO 1.5% Fail (Limit <=0.3%)
HC 92 PPM Pass
Lambda 0.97 Pass (Limit 0.97 - 1.03)

Second Fast Idle Test
CO 1.9% Fail (Limit <=0.3%)
HC 84 PPM Pass
Lambda 0.95 Fail (Limit 0.97 - 1.03)

Natural Idle test
CO 8.88% Fail (Limit <=0.5%)

A little bit better, but I'm not sure where to go next? I've asked around about the Cat but people seem to think it's more of a fuelling problem or sensing problem. I'm getting a Vag-Com next week to check if there's any other faults... But I'd really like your help if you can decipher the information - any suggestions much appreciated.

Thanks in advance

SwFsnapper

PS car has done 135,000 miles - serviced every 10k on average accept the last one which was at about 120k. I've carried out a through inspection of the inlet manifold and exhaust manifold, no obvious leaks. I've reset the ECU and took it for a good run. There is no secondary air pump fitted to this car that I can see as you find on some Mk1 Galaxys.

[Chrispb]

Firstly welcome to the forum

Not familiar with the petrol version but air and temperature sensors play a vital part in mixture control, but to try and take away some of the guess work wait until you have your Vagcom lead, as you said there could be other faults logged.
I do beleive some models have two lamda sensors not sure if that applies to your model though

[Madbaz]

If it's a 1996 it should have a secondary air pump (certainly on the 2.0 Gal), these do fail and usually pop the fuse in the battery fuse box.

I think on the Alhambra the pump is different to the Galaxy (iirc it might be around the air filter as opposed the battery on gals) but they do the same job.

The pump is activated for the first few minutes on starting from cold in order to get the cat up to temperature, if the ecu detects that the pump isn't working then incorrect signals are sent around the engine resulting in a MOT fail on emissions.

The fix: replace the pump, very expensive , or disconnect it and permanently put a 5w bulb across the electrical feeds, fooling the ecu into thinking the pump is working.

However after posting all this, I read the last line of your post , iirc mine failed on the CO on the idle, and then the HC on the fast idle.

[SilverBeast]

If it's a 2.0 petrol, I'm not sure VAG-COM will help as I believe that is a Ford engine and VAG-COM only works with the VW engines (diesel and V6 ?).  From memory (so don't take it as gospel and check some more)  of reading through this and other Forums you would need an ELM327 based ODB reader.

(Posts and waits to be corrected!)

[Chrispb]

The 2 litre petrol in the alhambra is the VW 2 litre not the Ford 2 litre in the galaxy

[SilverBeast]

(Posts and waits to be corrected!)

The 2 litre petrol in the alhambra is the VW 2 litre not the Ford 2 litre in the galaxy

Told you ! 

[Chrispb]

 

[swfsnapper]

Wow, Thanks for all the quick replies.

Just to keep you updated...

The VAG-COM cable turned up, I cleared the current fault codes which were basically "Lambda low" and "MAF intermittent fail" both of which I was expecting, because I know the Lambda is reading low and I had disconnected the MAF while the engine was running during previous checks. So both could be discounted. I ran the engine and checked again and the only fault code that reappeared was the Lambda low as shown below.

00537 - Lambda (Oxygen Sensor) Regulation
            19-10 - Lower Limit - Intermittent

But as I've said before I was kinda expecting that although I will keep an eye on it.

More interestingly was the readings off the engine while it was running. I didn't record them all down but basically the engine temp didn't get above 60 degrees Should be 80 at least huh? - so a stuck open thermostat me thinks.

Good bit of kit that VCDS =)

Also, a more through investigation found a leak in the Crank case/rocker cover vent pipe too the intake! and stupidly (Because I didn't check them before) I have also found the spark plugs badly worn.

So a bit of routine maintenance to carry out this week and I'll plug in the VAG-COM again to see what readings I get (Wish I had the full version)

I'll be back to report my findings.

Regards SwFsnapper

PS further to the other replies - Yup VAG-COM does work with the Alhambra 2.0i engine - still cant find the secondary air pump, but I would of expected to see it on the VAG-COM if it had failed? and the car only has one pre cat Lambda sensor.

[swfsnapper]

Hi,

Good news, after 3 hours work, Ã,£100 in materials and four tests, the Alhambra finally passed itââ,¬â,,¢s emissions test.

Emissions havenââ,¬â,,¢t been something Iââ,¬â,,¢ve had to worry about before and Itââ,¬â,,¢s been really interesting learning what the test results mean, how the car controls emissions and the numerous and varied components that can effect
emissions.

What I found disappointing is the lack of centralised information and easy findings regarding the subject, plus the number of forum posts that start the subject but the originator never comes back to report on the fix.

Not this postââ,¬Â¦. here is a list of all the things I did to get a fix and links to what I consider essential reading to help you make an informed decision regarding your emissions problem.

Work carried out on the car.

• Repaired any obvious leaks to the inlet manifold. The MOT tester found one on the brake boost pipe which I replaced and I found the other on the crank case/rocker cover  vent pipe.
• Cleaned the MAF, found a few black deposits on the testing wire, took 2 minutes to clean.



• Thermostat stuck open. Couldnââ,¬â,,¢t get the car temperature above 60 degrees. Should be between 90 and 110 I think i.e. temp needle pointing straight up


• Sparkplugs worn (replaced) and oil service req (Serviced - overdue by 5k)


• Injector cleaner put in tank with high octane petrol and Italian tune up (thrashed it down the motorway)


• Reset the ECU ââ,¬â€œ The car was running very rough after some of the work, but after disconnecting the negative battery terminal for 20 minutes, refitting and taking it for a long drive using the full throttle range, the ECU re-learnt the engine and the car now runs sweet as a nut.

You may have noticed that I didnââ,¬â,,¢t replace the CAT. I have to admit I did put a new Lambda sensor in, but it didnââ,¬â,,¢t make a blind bit of difference so I removed it and sold it on ebay.

Here are some essential reading to help you understand how the engine controls emissions.

http://www.petercoopercarrepairs.co.uk/new_page_2.htm

http://www.fpuk.co.uk/technical/ttl2.htm

Hope this helps someone, there's a lot of stuff to check and cheap items to replace before you start looking into CATs and worn rings. PM me if you have any questions.

Mark

[Mirez]

Interesting links - thanks for the info